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Stage-1 adult (A, B), female (C, E), stage-2 male (D), and late juvenile stage (J-5?; F) of Centroderes barbanigra n. sp. from Bermuda, SEM. A, B. Head, introvert sectors 7 and 8, left side (A) and sectors 6 and 7, dorsal view (B). C, D. Posterior segments with epibionts (arrows), left side. E. Segments 1−6 with sensory spot, attachment area of dorsoventral muscle, and secondary fringe, right side. F. Segments 1−4, left side. Notice thin body cuticle bulging irregularly. Arrowheads in C, E, and F mark sensory spots. Scale in A−F 10 µm.
Source publication
Four new species of Centroderes are described from the Northwest Atlantic Ocean based on light microscopical observations of 153 adult and 26 juvenile specimens and on SEM investigations of 54 adult and 3 juvenile specimens. Centroderes barbanigra n. sp. and C. bonnyae n. sp. can be distinguished from all other species by the existence of a short l...
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... at each side of the dorsoventral axis (Fig. 19A). The primary spinoscalids are finger-like, with a broad basis showing a central, flat tuft of hairs projecting outwards, and a second terminal bundle of hairs. The distal part of the primary spinoscalid is densely covered with tiny cuticular hairs at its proximal part, but is smooth more distally (Fig. 4A−B), with four or five transverse lines near its blunt end. The spinoscalids are formed by two parts as well: a proximal basis with fringes at its margin, and a distal, pointed shaft. A fringe of cuticular hairs is also found laterally of each spinoscalid on the introvert cuticle. The second ring (ring 02) consists of ten spinoscalids that ...
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... on the introvert cuticle. The second ring (ring 02) consists of ten spinoscalids that alternate in position with ring 01. Ring 02 spinoscalids are shorter than the primary ones, and show a needle-like shaft, projecting posteriorly from the broad proximal basis. Two spinoscalids flank the position of the ring 02 spinoscalids in the next ring (Fig. 4A, B), making a total of twenty spinoscalids in ring 03, with two spinoscalids in each sector. Their distal parts appear as long, flat triangles. A single spinoscalid located centrally in each section appears in the following rings, but its attachment point is shifted to an even more posterior position in every second ring, so that the ...
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... trichoscalids are present just posterior to ring 07 ( Figs 4A, B, 19A). One trichoscalid is located anterior to, and medially aligned with, each neck placid, except for the two placids located to each side of the midventral one. ...
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... and medially aligned with, each neck placid, except for the two placids located to each side of the midventral one. Here, each two placids have only one associated trichoscalid, and it is located anterior to the point where the two placids meet. All trichoscalids are relatively short, cone shaped, and densely covered with short, spinose processes (Fig. 4A, ...
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... narrow placids (width 9−11 µm) on either side. The widths of the remaining eleven placids alternate between broader (width 19−20 µm) and more narrow (width 9−11 µm) (Figs 4A, B, E, 6E). This series includes a narrow middorsal placid (Fig. 6E). The articulation between the placids and segment 1 is distinct. The surface of the placids is smooth (Fig. 4A, B, E), pores seem to occur deeper in the cuticle. Each placid, except the narrow ventromedial and ventrolateral ones, is linked to a trichoscalid, but only one pair of trichoscalids is associated with the two ventromedial and ventrolateral placids. This adds to a total of 14 ...
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... or less regularly in 4 (anterior segments) to 6 (more posterior segments) wavy lines which may be interrupted, especially on the sternal plates ( Figs 3E, 4E). The secondary fringe is often covered by the free flap of the precedent segment making observations more difficult. Anterior of the fringe, a narrow smooth area without any scales occurs (Fig. 4E). Few pore sites without an association with cuticular surface structures appear as a single row in light microscopy in the anterior third behind the secondary fringe of each segment. In addition, such pores occur in both females and males as a row in the anterior-posterior axis on each sternal plate of segment 11 and in females only as ...
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... plates reveals a single oval area without scales (Fig. 6B) but a slightly wrinkled surface. Usually, the free flap shows on all segments a weak, short, internal, longitudinal striation pattern (Fig. 6A, B). At the posterior margin of the sternal and tergal plates, all specimens reveal numerous short, cuticular processes, the pectinate fringe (Fig. 4E, F). Sensory spots appear on all segments in a characteristic pattern and are arranged bilateral symmetrically ( Figs 2, 3A, D, F, 4E, 6E, F; Tab. 5). Sensory spots contain usually 1−3 cuticular tubes extending through the body cuticle (Fig. 7A). Each tube widens up below the cuticle to form a cuticular funnel or cavity (Fig. 7A), and ...
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... exhibits three sternal plates on segments following segment 1 with distinctive intersternal junctions (Fig. 5A, B). In contrast to adult stages, the hair-like cuticular processes at the border between sternal and tergal plates are missing on segment 8 of the juvenile (Fig. 5B). The thin body cuticle results in an irregularly bulging cuticle (Fig. 4F). Segment 10 shows an acicular middorsal and an acicular laterodorsal spine ( Synonomy. Not Centroderes spinosus but C. bonnyae n. sp. -in , 1982, 1986Coull ...
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... midterminal spine. Such muscles can only be recognized in glycerin-paraffin mounts. Longitudinal muscles attach to the pachycycli of subsequent segments on the left and right side dorsally and ventrally in all segments. One pair of dorsoventral muscles, each consisting of two strands stretches between the tergal and sternal plate of each segment (Fig. 14E). Oblique muscles occur laterally in the anterior 9 segments. There are about 6−8 muscle strands in the more anterior segments but a single strand in segment 9. Head and mouth cone retractors as well as pharynx protractors appear in the anterior trunk (Fig. ...
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... of two strands stretches between the tergal and sternal plate of each segment (Fig. 14E). Oblique muscles occur laterally in the anterior 9 segments. There are about 6−8 muscle strands in the more anterior segments but a single strand in segment 9. Head and mouth cone retractors as well as pharynx protractors appear in the anterior trunk (Fig. ...
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... pharynx consists of an outer muscular bulb with alternating radial and circular muscle cells as well as one or two prepharyngeal sphincters and an inner epithelium. A postpharyngeal sphincter may or may not exist. The gut may contain up to 6 or even 17 diatom shells (Fig. 14A) per specimen belonging to probably the same amount of different species. Remnants of food or erroneously swallowed material occur in the midgut appearing as light- refractive or smaller, irregularly shaped, chaotic ...
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... a distinctively folded, strongly sclerotized cuticle around their gonoducts extending through the body cuticle. The free flap of segment 10 bends slightly in the area of the gonopores and reveals stronger and branching longitudinal striae (Fig. 13C, D). Gonads with eggs and sperm in the receptacula seminales are visible in several specimens (Fig. 14C, D, F). Gonads are capped anteriorly by cells without yolk (Fig. ...
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... gonoducts extending through the body cuticle. The free flap of segment 10 bends slightly in the area of the gonopores and reveals stronger and branching longitudinal striae (Fig. 13C, D). Gonads with eggs and sperm in the receptacula seminales are visible in several specimens (Fig. 14C, D, F). Gonads are capped anteriorly by cells without yolk (Fig. ...
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... any substructure. Another stage-2 female (USNM 1251512) exhibits one spermatophore with two thick-walled, spherical cavities (inner diameter 34 µm x 45 µm and 46 µm x 50 µm) ventrally at the border of segments 10 and 11 and a second spermatophore with two such chambers (inner diameter 28 µm x 31 µm and 47 µm x 61 µm) slightly more laterally (Fig. 14C). One chamber is filled with sperm, the other three chambers show a network-like substructure probably representing remnants of glandular material (Fig. 14C). A thick, light-refracting, worm-like structure (15 µm x 61 µm) attaches posterior and outside of the spermatophores (Fig. 14C). The receptacula seminales are filled with sperm ...
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... µm and 46 µm x 50 µm) ventrally at the border of segments 10 and 11 and a second spermatophore with two such chambers (inner diameter 28 µm x 31 µm and 47 µm x 61 µm) slightly more laterally (Fig. 14C). One chamber is filled with sperm, the other three chambers show a network-like substructure probably representing remnants of glandular material (Fig. 14C). A thick, light-refracting, worm-like structure (15 µm x 61 µm) attaches posterior and outside of the spermatophores (Fig. 14C). The receptacula seminales are filled with sperm (Fig. 14C, D). The gonads exhibit developing eggs (Fig. ...
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... 28 µm x 31 µm and 47 µm x 61 µm) slightly more laterally (Fig. 14C). One chamber is filled with sperm, the other three chambers show a network-like substructure probably representing remnants of glandular material (Fig. 14C). A thick, light-refracting, worm-like structure (15 µm x 61 µm) attaches posterior and outside of the spermatophores (Fig. 14C). The receptacula seminales are filled with sperm (Fig. 14C, D). The gonads exhibit developing eggs (Fig. ...
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... (Fig. 14C). One chamber is filled with sperm, the other three chambers show a network-like substructure probably representing remnants of glandular material (Fig. 14C). A thick, light-refracting, worm-like structure (15 µm x 61 µm) attaches posterior and outside of the spermatophores (Fig. 14C). The receptacula seminales are filled with sperm (Fig. 14C, D). The gonads exhibit developing eggs (Fig. ...
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... the other three chambers show a network-like substructure probably representing remnants of glandular material (Fig. 14C). A thick, light-refracting, worm-like structure (15 µm x 61 µm) attaches posterior and outside of the spermatophores (Fig. 14C). The receptacula seminales are filled with sperm (Fig. 14C, D). The gonads exhibit developing eggs (Fig. ...
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... lateral mount of one stage-2 male reveals a spermatophore 51 µm x 73 µm in size ventrally at the border of segments 10 and 11 (USNM 1251471: Fig. 14B; Neuhaus 2013: Fig. 5.1.13.B). This spermatophore consists of a single cavity partly filled with a small amount of sperm and a network-like substructure probably representing remains of glandular ...
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... of characters. The single stage-1 female from the Gulf of Mexico (USNM 1251552) shows slim and elongate middorsal spines on segments 1−9 (Fig. 14G), thin lateroventral spines on segments 8 and 9 (Fig 14G), a middorsal and a laterodorsal acicular spine on segment 10, a weakly developed cuticle, gonads with eggs, and gonopores. Female-specific, modified gland cell outlets appear in an intermediate position between lateroventrally and ventrolaterally on segment 8 and ventromedially ...
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... of characters. The single stage-1 female from the Gulf of Mexico (USNM 1251552) shows slim and elongate middorsal spines on segments 1−9 (Fig. 14G), thin lateroventral spines on segments 8 and 9 (Fig 14G), a middorsal and a laterodorsal acicular spine on segment 10, a weakly developed cuticle, gonads with eggs, and gonopores. Female-specific, modified gland cell outlets appear in an intermediate position between lateroventrally and ventrolaterally on segment 8 and ventromedially on segment 9. The specimen is smaller but exhibits longer middorsal spines on segments 7−9 (Tab. ...
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... muscles attach to the pachycycli of subsequent segments on the left and right side dorsally and ventrally in all segments (Fig. 24C). One pair of dorsoventral muscles, each consisting of two strands stretches between the tergal and sternal plate of each segment. Oblique muscles occur laterally in the anterior 9 segments. There are about 6−8 muscle strands in the more anterior segments but a single strand in segment ...
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... two specimens of an earlier juvenile stage from Massachusetts (USNM 1251589, 1251590; mounted for LM) and the specimen from Florida (USNM 1251597 specimen 03) possess numerous postmarginal spicules of different lengths at the posterior border of sternal and tergal plates (Fig. 24D). In one specimen, the scales and the thin spinose processes at the posterior border of each sternal plate are much more pronounced in the midventral area than in more lateral parts. In this area, the scales are also slightly larger. At least two earlier juvenile specimens lack the midventral spinose process on segment 1 and seem to ...
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... and bold. Sensory spots not occuring in all specimens but in some are put in ( ); rare characters are in (( )). For sensory spots of C. readae n. sp. compare also One individual from Massachusetts (USNM 1251591) and one from Newfoundland (USNM 1251570) are moulting from a juvenile to the stage-1 female, both with two gonads with developing eggs ( Fig. 24J; Tabs 8, 9). Whereas the former specimen reveals no gonopore in both the old and the new cuticle, the latter specimen shows a weakly sclerotized gonopore only in the new but not in the old cuticle (Fig. 24G, H). Segments 2−11 of the juvenile exuvia reveal two sternal plates per segment (Fig. 24F). Neither animal exhibits on the old or new cuticle ...
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... and one from Newfoundland (USNM 1251570) are moulting from a juvenile to the stage-1 female, both with two gonads with developing eggs ( Fig. 24J; Tabs 8, 9). Whereas the former specimen reveals no gonopore in both the old and the new cuticle, the latter specimen shows a weakly sclerotized gonopore only in the new but not in the old cuticle (Fig. 24G, H). Segments 2−11 of the juvenile exuvia reveal two sternal plates per segment (Fig. 24F). Neither animal exhibits on the old or new cuticle a modified gland cell outlet on segment 7−9, but the outlet may have been cleared by Hoyer's mounting medium in the Newfoundland specimen. Both specimens possess a midventral spinose process on ...
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... female, both with two gonads with developing eggs ( Fig. 24J; Tabs 8, 9). Whereas the former specimen reveals no gonopore in both the old and the new cuticle, the latter specimen shows a weakly sclerotized gonopore only in the new but not in the old cuticle (Fig. 24G, H). Segments 2−11 of the juvenile exuvia reveal two sternal plates per segment (Fig. 24F). Neither animal exhibits on the old or new cuticle a modified gland cell outlet on segment 7−9, but the outlet may have been cleared by Hoyer's mounting medium in the Newfoundland specimen. Both specimens possess a midventral spinose process on segment 1 as well as a middorsal and a laterodorsal acicular spine on segment 10 in both the ...
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... animal exhibits on the old or new cuticle a modified gland cell outlet on segment 7−9, but the outlet may have been cleared by Hoyer's mounting medium in the Newfoundland specimen. Both specimens possess a midventral spinose process on segment 1 as well as a middorsal and a laterodorsal acicular spine on segment 10 in both the old and new cuticle (Fig. 24E). A weak secondary fringe seems to exist in the specimen from ...
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... one female from Massachusetts (USNM 1251571), the tergal plate of segment 6 terminates on the right side about midlaterally (Fig. 24B, C). From there on, the tergal plate of segment 5 broadens on the right side and meets the right sternal plate of segment 5 only with its anterior edge; the tergal plate also borders the sternal plate of segment 6 over its entire length giving the impression of a "regular" tergal plate of segment 6 (Fig. 24A). The right sternal plate of ...
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... on the right side about midlaterally (Fig. 24B, C). From there on, the tergal plate of segment 5 broadens on the right side and meets the right sternal plate of segment 5 only with its anterior edge; the tergal plate also borders the sternal plate of segment 6 over its entire length giving the impression of a "regular" tergal plate of segment 6 (Fig. 24A). The right sternal plate of segment 5 reveals a shortened lateral margin with rounded edges, whereas the left sternal plate exhibits a regular shape (Fig. 24A). The right lateroventral spine on segment 5 appears in an almost ventromedial position (Fig. 24A). A sublateral sensory spot occurs on the right side on segment 5 but not on the ...
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... of segment 5 only with its anterior edge; the tergal plate also borders the sternal plate of segment 6 over its entire length giving the impression of a "regular" tergal plate of segment 6 (Fig. 24A). The right sternal plate of segment 5 reveals a shortened lateral margin with rounded edges, whereas the left sternal plate exhibits a regular shape (Fig. 24A). The right lateroventral spine on segment 5 appears in an almost ventromedial position (Fig. 24A). A sublateral sensory spot occurs on the right side on segment 5 but not on the left side. The tergal plate of segment 6 shows only a right but not a left subdorsal sensory spot, as well as a left but not a right laterodorsal sensory spot. ...
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... 6 over its entire length giving the impression of a "regular" tergal plate of segment 6 (Fig. 24A). The right sternal plate of segment 5 reveals a shortened lateral margin with rounded edges, whereas the left sternal plate exhibits a regular shape (Fig. 24A). The right lateroventral spine on segment 5 appears in an almost ventromedial position (Fig. 24A). A sublateral sensory spot occurs on the right side on segment 5 but not on the left side. The tergal plate of segment 6 shows only a right but not a left subdorsal sensory spot, as well as a left but not a right laterodorsal sensory spot. A cuticular spinose process originates about midlaterally on segment 5 on the right side (Fig. ...
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... position (Fig. 24A). A sublateral sensory spot occurs on the right side on segment 5 but not on the left side. The tergal plate of segment 6 shows only a right but not a left subdorsal sensory spot, as well as a left but not a right laterodorsal sensory spot. A cuticular spinose process originates about midlaterally on segment 5 on the right side (Fig. 24C) and laterodorsally on segment 6 on the left side (Fig. 24B). The right protonephridium opens on segment 9 through few pores surrounded by a horseshoe-shaped, strongly sclerotized cuticular ridge, whereas the left nephropore area appears normal. . Frequency of occurrence of sensory spots and papillae on segments of populations of ...
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... right side on segment 5 but not on the left side. The tergal plate of segment 6 shows only a right but not a left subdorsal sensory spot, as well as a left but not a right laterodorsal sensory spot. A cuticular spinose process originates about midlaterally on segment 5 on the right side (Fig. 24C) and laterodorsally on segment 6 on the left side (Fig. 24B). The right protonephridium opens on segment 9 through few pores surrounded by a horseshoe-shaped, strongly sclerotized cuticular ridge, whereas the left nephropore area appears normal. . Frequency of occurrence of sensory spots and papillae on segments of populations of Centroderes readae n. sp. n = 25 for populations from Florida ...
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... single female specimen from the Gulf of Mexico (USNM 1251552) is tentatively assigned to C. drakei n. sp. known otherwise from Bermuda (Tab. 8), because it agrees in almost all characters with the latter species. However, it disagrees in the middorsal spine of segments 1−9 and the lateroventral spines on segments 8−9 being thinner (Fig. 14G) and the middorsal spines being longer on segments 7−9 (Tab. 3), in the existence of an acicular middorsal and laterodorsal spine on segment 10 (but see following chapter and below), and in the modified female- specific gland cell outlets being located slightly more ventromedially than in other specimens of the species from Bermuda. In ...
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... of segment 11 a female gonopore, eggs or sperm in the gonads, or the crenulated middorsal and laterodorsal spine on segment 10 of the male. The female-specific gland cell outlet on posterior segments seems to be recognizable only in more aged adult females, because it cannot be traced in two females of C. readae n. sp. (USNM 1251591, 1251570: Fig. 24G, H) moulting from juvenile stages and not in one female of C. drakei n. sp. (USNM 1251509) moulting from stage-2 to stage-2 (Tab. 8). Gonads may exist already in late juvenile stages and can often not be identified as female or male at an early stage of the gonads's development. Late juvenile stages seem to possess the full pattern of ...
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... another female (acicular spines on segment 10). Whereas female C. readae n. sp. reveal gonopores and the female-specific gland cell outlets on posterior segments, these characters are missing in stage-1 females of C. drakei n. sp. and C. spinosus ( Tabs 8, 9;). (Neuhaus 2013: p. 259). Whereas the male studied yields just one spermatophore chamber (Fig. 14B), one female carries a two-chambered spermatophore and another female even four chambers. The arrangement of the chambers in the latter specimen (Fig. 14C) suggests that the female copulated twice. The finding of sperm in the chamber of one male (Neuhaus 2013: Fig. 5.1.13B) and one female (Fig. 14C) of C. drakei n. sp. also lays to rest ...
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... these characters are missing in stage-1 females of C. drakei n. sp. and C. spinosus ( Tabs 8, 9;). (Neuhaus 2013: p. 259). Whereas the male studied yields just one spermatophore chamber (Fig. 14B), one female carries a two-chambered spermatophore and another female even four chambers. The arrangement of the chambers in the latter specimen (Fig. 14C) suggests that the female copulated twice. The finding of sperm in the chamber of one male (Neuhaus 2013: Fig. 5.1.13B) and one female (Fig. 14C) of C. drakei n. sp. also lays to rest the hypothesis that the brownish mucous mass are eggs as suggested previously (Nyholm 1947;Higgins 1965Higgins , 1974. For the first time, a spermatophore ...
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... studied yields just one spermatophore chamber (Fig. 14B), one female carries a two-chambered spermatophore and another female even four chambers. The arrangement of the chambers in the latter specimen (Fig. 14C) suggests that the female copulated twice. The finding of sperm in the chamber of one male (Neuhaus 2013: Fig. 5.1.13B) and one female (Fig. 14C) of C. drakei n. sp. also lays to rest the hypothesis that the brownish mucous mass are eggs as suggested previously (Nyholm 1947;Higgins 1965Higgins , 1974. For the first time, a spermatophore is reported here for both female and male (!) specimens of a kinorhynch ...
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... RH-103.SEM34) and C. drakei n. sp. (USNM 1251509; RH-103.SEM37) as filamentous, segmented specimens of variable length (algae?, fungi?) attaching to the posterior segments (Figs 4C, D, 11E). Similar epibionts have also been photographed on Echinoderes applicitus Ostmann et al., 2012 but not further identified (see Ostmann et al. 2012: Fig. 6C, E). ...
Citations
... This contribution increased the number of known Caribbean kinorhynch species to Mar Biodiv 19, with the description of 5 new species of Cyclorhagida and 13 species of Allomalorhagida (Higgins 1983). More recently, the area of Bocas del Toro, Colón Island and Bastimento Island (Panama) has been extensively studied by Sørensen (2006), Neuhaus et al. (2014) and Pardos et al. (2016a, b), resulting in 5 new species of Cyclorhagida, 2 new species of Allomalorhagida and 7 new reports, bringing the total number of valid kinorhynch species for the Caribbean Sea up to 31. ...
... Cristaphyes belizensis, Echinoderes abbreviatus, Fujuriphyes deirophorus, Higginsium erismatum (Higgins, 1983), H. trisetosum (Higgins, 1983), Leiocanthus corrugatus (Higgins, 1983), L. ecphantor (Higgins, 1983), Pycnophyes apotomus (Higgins, 1983), P. stenopygus (Higgins, 1983) and Setaphyes iniorhaptus (Higgins, 1983 (Higgins, 1983) and Paracentrophyes praedictus Higgins, 1983. 6. Eleven species found both inside and outside the Caribbean Sea: Antygomonas paulae Sørensen, 2007, Centroderes barbanigra Neuhaus et al., 2014, Echinoderes astridae, E. horni, E. intermedius Sørensen, 2006, E. parahorni sp. nov. ...
... Samples of meiofauna from the Caribbean Sea and adjacent waters collected by Dr R. P. Higgins in 1976 and1980 and deposited in the Smithsonian National Museum of Natural History of Washington (NMNH) gave the authors the opportunity to study several specimens of Dracoderes from Hispaniola Island, the second largest land mass of the Greater Antilles after Cuba, where kinorhynchs have been scarcely studied. There are few papers dealing with the biodiversity of this phylum in the Caribbean Sea (Kirsteuer 1964;Higgins 1983;Sørensen 2006;Neuhaus et al. 2014;Pardos et al. 2016). The present study contributes to the understanding of the taxonomy and biogeographical distribution of the allomalorhagid Dracoderes as well as to the knowledge of kinorhynch biodiversity of the Caribbean Sea and adjacent waters. ...
... This led the authors to suggest that females with middorsal spines on the two posteriormost segments represented a first adult stage, which would moult into a second adult stage and lose the middorsal spines in the process. Shortly after this finding, Neuhaus et al. (2014) were, in an even more comprehensive study, able to demonstrate that adult moulting resulting in two dimorphic stages appeared to be common among species of Centroderes Zelinka, 1907. In all observed cases, the dimorphism was expressed as absence/presence of spines on the two posteriormost segments, which is analogous to the findings in Campyloderes. ...
... As summarized in the Introduction, adult dimorphism has so far been confirmed from a single species or more from the genera Echinoderes, Campyloderes, Centroderes and Condyloderes (Higgins, 1977a;Neuhaus & Sørensen, 2013;Neuhaus et al., 2014;Sørensen et al., 2019), and now also of Sphenoderes. In addition, adult moulting was observed in species of Cateria Gerlach, 1956, Zelinkaderes and Antygomonas (Higgins, 1990;Bauer-Nebelsick, 1996;Neuhaus & Kegel, 2015). ...
Adult dimorphism (i.e. non‐sexual dimorphism observed among sexually mature specimens) and the existence of two morphologically distinct adult stages are for the first time reported from a species of the kentrorhagid kinorhynch genus Sphenoderes. The dimorphism was found in a new species, Sphenoderes neptunus sp. nov., from the Gulf of Naples, Italy, and a formal description is provided. While dimorphism between adult life stages of kinorhynchs so far have been restricted to differences in the two posteriormost segments, the dimorphism in the new species is expressed in spine lengths throughout the entire trunk, as well as in presence or absence of cuspidate spines. The implications for comparative kinorhynch morphology and taxonomy are discussed, and it is concluded that adult dimorphism and the occurrence of more than one adult life stage always should be considered as a possibility when exploring kinorhynchs of the orders Kentrorhagata and Xenosomata. Despite the comparative challenges prompted by the adult dimorphism, species of Sphenoderes can still be distinguished by differences in shape of midventral placid and distribution of sensory spots. Conversely, spine patterns as differential characters should be used with caution, and only after ensuring that specimens belonging to the same adult stage are compared.
... Until now, kinorhynchs were found from 12 caves in the north Caribbean Sea, Canary Islands (Atlantic Ocean), western to middle Mediterranean Sea, Atolls of the Maldives (Indian Ocean), southern Japan (Pacific Ocean) and eastern Australia (Coral Sea) . Of the specimens found in these caves, some were identified as putative taxa and others reported as belonging to the following eight nominal species: Centroderes barbanigra Neuhaus et al., 2014 (ICHUM 5976), whole animal, dorsal and ventral view, respectively; (C, D) paratype male (ICHUM 5977), segments 9-11, dorsal and ventral view, respectively. Abbreviations: gco1/2, type-1/2 gland cell outlet; ldt, laterodorsal tube; ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral acicular spine; lvt, lateroventral tube; mds, middorsal acicular spine; pe, penile spine; si, sieve plate; slt, sublateral tube; ss, sensory spot; trp, trichoscalid plate. ...
Three new species of echinoderid kinorhynchs are described from Daidokutsu, a submarine cave in Ryukyu Islands, Japan. Echinoderes gama sp. nov. is characterized by the presence of middorsal acicular spines on segments 4–8; lateroventral acicular spines on segments 7–9; lateroventral tubes on segment 5; sublateral tubes on segment 8; laterodorsal tubes on segment 10; and type-2 gland cell outlets in subdorsal and lateroventral position on segment 2. Echinoderes kajiharai sp. nov. is defined by the presence of middorsal acicular spines on segments 4, 6, 8; lateral accessory acicular spines on segment 9; lateroventral acicular spines on segments 6–8; lateroventral tubes on segments 2 and 5; midlateral tubes on segment 10; and type-2 gland cell outlets in laterodorsal position on segments 2 and 5, and subdorsal position on segments 8 and 9. Echinoderes uozumii sp. nov. is characterized by the presence of middorsal acicular spines on segments 4 and 6; lateroventral acicular spines on segments 6–9; lateroventral tubes on segments 2 and 5; sublateral tubes on segment 8; laterodorsal tubes on segment 10; type-2 gland cell outlets in subdorsal and lateral accessory position on segment 2; and blunt, short pectinate fringe teeth of primary pectinate fringe on segment 1. In addition, the Echinoderes multiporus species group including E. kajiharai sp. nov., and the Echinoderes bispinosus species group including E. uozumii sp. nov. are established. Furthermore, the distribution of the two species groups and the origin of Echinoderes species in Daidokutsu are discussed
... Our material showed the characters defining the monotypical genus Franciscideres Dal Zotto et al., 2013. The specific identification faces the taxonomical conflict arising from the insufficiency of the original information about the type species and the recent evidence that Kinorhyncha species can show a considerably larger intraspecific variability than previously assumed (Neuhaus & Sørensen 2013;Neuhaus & Kegel 2015;Neuhaus et al. 2014Neuhaus et al. , 2019Sánchez et al. 2019;. Though intraspecific variation was rarely thought to be important for the taxonomy of kinorhynchs (Sørensen & Pardos 2008;Dal Zotto et al. 2013;Yamasaki 2016Yamasaki , 2017, the huge variation described for some species (e.g., Neuhaus et al. 2019;Sánchez et al. 2019) highlights a change of mind and emphasizes the need of paying attention to such variation. ...
... Several other characters observed in the Argentinian specimens were not described for the Brazilian material, but we cannot rule out that they are present also in these populations, viz, (1) presence of ventrolateral tubes on segment 1, (2) introvert features, (3) each segment composed of a closed cuticular ring, (4) trunk cuticle ornamented by a secondary fringe of knob-like structures, (5) ventral free flap of segment 10 terminating in two lateral and one broad triangular lobes, (6) ventral free flap of segment 11 centrally terminating in four lobes, (7) lateral terminal spines armed with thorn-like processes, (8) pores/sensory spots/glands distribution and (9) sexual dimorphism in segments 10 and 11 (Tables 4,5). In addition, some of the differences noted (Tables 4, 5) are probably compatible with the amount of species-specific variation now recognized in other Kinorhyncha species (Neuhaus & Sørensen 2013;Neuhaus et al. 2014Neuhaus et al. , 2019Neuhaus & Kegel 2015;Sánchez et al. 2019;. ...
... The observed morphological differences of the animals collected in Argentina are interpreted as morphological variation or may have been overlooked in the Brazilian specimens. Recent articles found that intraspecific variation may be considerably larger in Kinorhyncha than previously assumed and our results seem to support these observations (Neuhaus & Sørensen 2013;Neuhaus et al. 2014Neuhaus et al. , 2019Neuhaus & Kegel 2015;Sánchez et al. 2019;. ...
Samples collected from Monte Hermoso, Buenos Aires Province, Argentina revealed the presence of specimens of the genus Franciscideres Dal Zotto et al., 2013, previously known only from Brazil. This morphotype seems to differ from the only known species, Franciscideres kalenesos Dal Zotto et al., 2013, in the following characters: (1) presence of ventrolateral tubes on segment 1, (2) introvert features, (3) each segment composed of a closed cuticular ring, (4) trunk cuticle ornamented by a secondary fringe of knob-like structures, (5) posterior margin of segment 10 ventrally terminating in two lateral and one broad triangular lobes, (6) posterior margin of segment 11 centrally terminating in four lobes (7) lateral terminal spines armed with thorn-like processes, (8) pores/sensory spots/gland cells distribution and (9) sexual dimorphism in segments 10 and 11. Because of the lack of full information about F. kalenesos from Brazil, we consider the new exemplars as Franciscideres cf. kalenesos. Additionally, we provide new information about the movement of this species using light microscopy and we compare these movements with those of other meiofaunal inhabitants.
... Traditionally, all original descriptions of new kinorhynch species have been accompanied by standard measurements of the body trunk, body segments and cuticular appendages (e.g. Higgins, 1977b;Sánchez et al., 2013;Neuhaus et al., 2014;Sørensen et al., 2016) carried out by a few specialists, which minimizes bias and error when taking the measurements. Thus, kinorhynchs are an ideal model for the study of allometric relationships, owing to their conserved morphology and the high standardization of metric data from descriptions of new taxa. ...
... When performing separate analysis for the families, similar results were obtained to those for the corresponding classes. Nevertheless, the cyclorhagid family Centroderidae yielded a negative allometric trend for the second trunk segment despite the presence of proportionally longer ventrolateral tubes (Neuhaus et al., 2014). In this family, the selection pressure towards retaining a negative allometric trend in the anterior segments seemed to be stronger and counteracted that of favouring the positive allometry because of the presence of ventrolateral tubes. ...
... In echinoderid Cyclorhagida, segment 11 possesses the dorsal cuticular plates extended to form the tergal extensions (Sørensen & Pardos, 2008;, and there are paired tergal extension muscles associated with the basal part of these extensions and anteriorly attached to the segment 11 pachycyclus (Herranz et al., 2014). The lateral terminal spines start their development from the earlier juvenile stages (Higgins, 1974;Neuhaus, , 2017Neuhaus & Sørensen, 2013;Neuhaus et al., 2014;Neuhaus & Kegel, 2015). In a similar way to the first trunk segments, the early development of the posterior body region could be responsible for the negative allometric trends observed for S11. ...
Allometry determines relevant modifications in metazoan morphology and biology and is affected by many different factors, such as ontogenetic constraints and natural selection. A linear mixed model approach and reduced major axis regression were used to explore evolutionary interspecific allometric trends between the total trunk length and the lengths of the segments and spines in the phylum Kinorhyncha at three taxonomic levels: the whole phylum, the class and the family. Statistically significant results were found in all the trunk segments, meaning that these body units grow proportionally correlated with the body, contrary to the results obtained for the spines. Developmental and morphophysiological constraints could lead to negative allometry in the first and last segments, because these body regions in kinorhynchs are essential to the implementation of some of the main biological functions, such as feeding and locomotion. The differential arrangement of cuticular appendages between the taxonomic groups considered seems to cause different evolutionary trends, because positive allometry may appear if a segment requires more space to accommodate a large number of organs and appendages, and vice versa. The presence of sexual dimorphism could also define positive allometry of a segment, owing to the need to harbour the sexually dimorphic appendages and their associated structures.
... 19, with the description of 5 new species of Cyclorhagida and 13 species of Allomalorhagida (Higgins 1983). More recently, the area of Bocas del Toro, Colón Island and Bastimento Island (Panama) has been extensively studied by Sørensen (2006), Neuhaus et al. (2014) and Pardos et al. (2016a, b), resulting in 5 new species of Cyclorhagida, 2 new species of Allomalorhagida and 7 new reports, bringing the total number of valid kinorhynch species for the Caribbean Sea up to 31. ...
Several meiofaunal samplings along the continental slope of Central America and the Antilles through the Caribbean Sea have revealed a rich kinorhynch fauna of undescribed species. The present contribution includes the description of two new species of the allomalorhagid genera Cristaphyes Sánchez et al., 2016 and Fujuriphyes Sánchez et al., 2016 and two new species of the cyclorhagid genus Echinoderes Claparède, 1863, as well as the first record of the previously known Cristaphyes longicornis (Higgins, 1983), Echinoderes astridae Sørensen, 2014, Echinoderes horni Higgins, 1983, Echinoderes imperforatus Higgins, 1983 and Echinoderes spinifurca Sørensen et al., 2005 for Haiti and the Dominican Republic (Hispaniola Island, Greater Antilles) together with new morphological information of the former. All the new species are formally described. Furthermore, we discuss the possibility of an expansion in the intraspecific morphological variation of C. longicornis, geographical remarks on the Caribbean Kinorhyncha and compare the morphological differences between the newly described species and their most similar congeners.
... Neuhaus & Blasche 2006;Herranz et al. 2012;Yamasaki et al. 2018a, b); middorsal and subdorsal/laterodorsal spines on segment 10 in kentrorhagid and campyloderid species (e.g.,Herranz et al. 2014;Yamasaki 2016;Neuhaus 2017;; and ventromedial tubes on segment 2 and penile spines in pycnophyid species(e.g., S anchez et al. 2016, 2018). More recently, intraspecific variation of middorsal and midlateral spines on segment 10 was documented also between different adult stages of Centroderes and Condyloderes(Neuhaus et al. 2014;Sørensen et al. 2019).However, variation in spine/tube pattern not related to the sexual and/or developmental dimorphism was observed in species of Campyloderes, Centroderes, and CondyloderesNeuhaus et al. , 2014Neuhaus et al. , 2019Dal Zotto et al. 2019). The major variation occurring in species of Condyloderes regards cuspidate spinesDal Zotto et al., 2019), which are hypothetical homologous to the tubules in Franciscideres kalenesos DalZotto et al., 2013 (e. g., Dal Zotto et al. 2013 and possibly to the tubes in species of Echinoderidae, too.Other variation not deriving from sexual and/or developmental dimorphism was also recently reported from some echinoderid species: Echinoderes dubiosus Sørensen et al., 2018 with tubes on segment 8 switching between midlateral and lateral accessory positions; Echinoderes daenerysaeGrzelak & Sørensen, 2017: ventrolateral tubes on segment 2 present/absent; Echinoderes rhaegaliGrzelak & Sørensen, 2017: sublateral tubes on segment 2 present/ absent; Echinoderes eximusHiggins & Kristensen, 1988: sublateral tubes on segment 9 present/absent; Echinoderes levanderiKarling, 1954: subdorsal tubes on segment 2 present/absent; and Fissuroderes higginsiNeuhaus, 2006in Neuhaus & Blasche (2006: dorsal tubes on segment 2 switching between laterodorsal and subdorsal positionsSørensen 2018;. ...
... Neuhaus & Blasche 2006;Herranz et al. 2012;Yamasaki et al. 2018a, b); middorsal and subdorsal/laterodorsal spines on segment 10 in kentrorhagid and campyloderid species (e.g.,Herranz et al. 2014;Yamasaki 2016;Neuhaus 2017;; and ventromedial tubes on segment 2 and penile spines in pycnophyid species(e.g., S anchez et al. 2016, 2018). More recently, intraspecific variation of middorsal and midlateral spines on segment 10 was documented also between different adult stages of Centroderes and Condyloderes(Neuhaus et al. 2014;Sørensen et al. 2019).However, variation in spine/tube pattern not related to the sexual and/or developmental dimorphism was observed in species of Campyloderes, Centroderes, and CondyloderesNeuhaus et al. , 2014Neuhaus et al. , 2019Dal Zotto et al. 2019). The major variation occurring in species of Condyloderes regards cuspidate spinesDal Zotto et al., 2019), which are hypothetical homologous to the tubules in Franciscideres kalenesos DalZotto et al., 2013 (e. g., Dal Zotto et al. 2013 and possibly to the tubes in species of Echinoderidae, too.Other variation not deriving from sexual and/or developmental dimorphism was also recently reported from some echinoderid species: Echinoderes dubiosus Sørensen et al., 2018 with tubes on segment 8 switching between midlateral and lateral accessory positions; Echinoderes daenerysaeGrzelak & Sørensen, 2017: ventrolateral tubes on segment 2 present/absent; Echinoderes rhaegaliGrzelak & Sørensen, 2017: sublateral tubes on segment 2 present/ absent; Echinoderes eximusHiggins & Kristensen, 1988: sublateral tubes on segment 9 present/absent; Echinoderes levanderiKarling, 1954: subdorsal tubes on segment 2 present/absent; and Fissuroderes higginsiNeuhaus, 2006in Neuhaus & Blasche (2006: dorsal tubes on segment 2 switching between laterodorsal and subdorsal positionsSørensen 2018;. ...
The two kinorhynch species Echinoderes capitatus (Zelinka, 1928) and Echinoderes ferrugineus Zelinka, 1928 are redescribed herein, based on specimens collected at different Mediterranean locations. Echinoderes capitatus is characterized by the presence of middorsal acicular spine on segment 4 and lateroventral acicular spines on segments 6–9; at least three pairs of tubes on segment 2 (subdorsal, midlateral, and ventrolateral); subdorsal tubes on segment 8; laterodorsal tubes on segment 10; lateral accessory tubes on segments 5 and 8; subdorsal sensory spots on segments 1 and 3–11; and ventromedial sensory spots on segments 2 and 5–7, often additionally on segment 8; occurrence of subdorsal tubes on segments 6 and 7, laterodorsal tubes on segment 2, midlateral tubes on segments 7 and 8, and ventromedial tubes on segment 8 showing intraspecific variation; and the absence of the type-2 gland cell outlets. The pattern of the additional tubes is relatively well-preserved within a population but differs among populations. Echinoderes ferrugineus is characterized by the presence of middorsal acicular spines on segment 4–8; lateroventral acicular spines on segments 6–9; lateral accessory tubes on segment 5; type-2 gland cell outlets in subdorsal, laterodorsal, sublateral, and ventrolateral position on segment 2, subdorsal and midlateral position on segment 4, midlateral position on segment 5, and midlateral position on segment 8; long lateral terminal spines (ca. 140–180 μm, 45–63% of trunk length). Comments are provided on the intraspecific variation in tube pattern in E. capitatus, and its potential importance in a speciation and evolutionary context.
... Samples of meiofauna from the Caribbean Sea and adjacent waters collected by Dr R. P. Higgins in 1976 and1980 and deposited in the Smithsonian National Museum of Natural History of Washington (NMNH) gave the authors the opportunity to study several specimens of Dracoderes from Hispaniola Island, the second largest land mass of the Greater Antilles after Cuba, where kinorhynchs have been scarcely studied. There are few papers dealing with the biodiversity of this phylum in the Caribbean Sea (Kirsteuer 1964;Higgins 1983;Sørensen 2006;Neuhaus et al. 2014;Pardos et al. 2016). The present study contributes to the understanding of the taxonomy and biogeographical distribution of the allomalorhagid Dracoderes as well as to the knowledge of kinorhynch biodiversity of the Caribbean Sea and adjacent waters. ...
A new species of Dracoderes, D. spyro sp. nov., is described from Hispaniola Island 16 (Caribbean Sea), and represents the first record of this genus in American waters. The 17 new species is distinguished from its congeners by the presence of lateroventral spines 18 on segments 3–4 and 6–9, lateral accessory spines on segment 5, lateroventral tubes on 19 segments 2, 5 and 10, and laterodorsal tubes on segment 8. Additionally, a dichotomous 20 key to the species level for the genus Dracoderes is included.
... Herein we describe two new species of the rare genus Condyloderes, report the presence of Condyloderes multispinosus (McIntyre, 1962) from the Mediterranean Sea and describe the female morphology of the adult stage of this species, which was not known before (McIntyre 1962;Higgins 1969;Neuhaus et al. 2019). The genus Condyloderes currently consists of six species ) plus two additional formally described species by Sørensen et al. (2019), and belongs to a phylogenetically debated order and family, i.e., Kentrorhagata and Centroderidae, respectively (Dal Zotto et al. 2013;Yamasaki et al. 2013;Neuhaus et al. 2014;Sørensen et al. 2015). Traditionally, Condyloderes together with Centroderes and Campyloderes composed the family Centroderidae. ...
... It was noted that a single female specimen had an indistinct mass of material which may be interpreted as a spermatophore attached to the terminal part of its trunk (Fig. S1A). This would be the second report of potential spermatophore in a cyclorhagid, after the finding in Centroderes drakei Neuhaus, Pardos, Sørensen & Higgins, 2014 (see Neuhaus et al. 2014). The spermatophore was present in both females and male in the species of this closely related genus. ...
... If the trigger would be seasonal, e. g., one would find different adult stages at a given time e or not at all. Most descriptions of species of Centroderes and Condyloderes are based on samples taken at one or few time slots (Higgins 1969;Adrianov et al. 2002;Martorelli & Higgins 2004;Sørensen et al. 2010Sørensen et al. , 2019Adrianov & Maiorova 2016;Neuhaus et al. 2014Neuhaus et al. , 2019this paper). ...
Two new species of Kinorhyncha belonging to the genus Condyloderes (Cyclorhagida: Centroderidae) are described herein. The specimens were collected in the Gulf of Castellammare (Tyrrhenian Sea, Sicily, Southern Italy) and off Livorno (Ligurian Sea, Tuscany, Central Italy), respectively. The new taxa represent the first species of Condyloderes described from the Mediterranean basin. Condyloderes agnetis sp. nov. is distinguished from its congeners by bearing cuspidate spines on segment 3 – a character never reported before for Cyclorhagida – in subdorsal position, paradorsally and sublaterally on segment 7, an extremely short midterminal spine, and a combination of cuspidate spines in lateral accessory position on segments 2 and 9, ventrolaterally slightly displaced ventromedially on segment 5, and ventrolaterally on segment 8. Condyloderes clarae sp. nov. is characterized by a combination of cuspidate spines on segments 5, 8, and 9 only, cuspidate spines ventrolaterally on segment 8 and in a lateral accessory position on segment 9, ventromedial appendages on segments 5, 6, and 7 in females. Both species exhibit the recently described type-6 sensory spots. Furthermore, the female morphology and data on the distribution of C. multispinosus (McIntyre, 1962) within the Mediterranean Sea are reported, along with the record of the co-occurrence of different species of Condyloderes at the same site. We report a certain degree of intraspecific variation of taxonomically diagnostic characters like the presence or absence of cuspidate spines and sensory spots on some segments in C. agnetis sp. nov. and C. multispinosus. The presence of regularly arranged cuticular hairs on most trunk segments and of an acicular spine in lateral accessory position on segment 1, along with the absence of an area of micropapillae on segment 9 in females of C. agnetis sp. nov. and C. clarae sp. nov., unique within the genus, suggest the existence of distinct evolutionary lines within Condyloderes. The discovery of the two new species highlights the potential species richness of a genus considered species-poor until recently. Our findings underscore the importance of promoting further studies even in rather well investigated areas, such as the Mediterranean basin. Beyond the taxonomic and biogeographical interest, the data reported herein provides additional insights for ongoing taxonomic and phylogenetic investigations on the Centroderidae and allies, and on the whole Cyclorhagida.
... Before this century, the known species richness in the gulf included three species in the genera Echinoderes Claparède, 1863, and Leiocanthus (Chitwood 1951Harper et al. 1981). Subsequent studies have reported 21 species in the genera Antygomonas Nebelsick, 1990, Campyloderes Zelinka, 1907, Centroderes Zelinka, 1907, Echinoderes, Leiocanthus, Paracentrophyes Higgins, 1983, Pycnophyes Zelinka, 1907, Semnoderes Zelinka, 1907, and Sphenoderes Higgins, 1969(Shirley 2009Neuhaus and Sørensen 2013;Neuhaus et al. 2014;Sørensen and Landers 2014, 2017Sørensen et al. 2016a;Sørensen 2016, 2018;Landers et al. , 2019. From our Gulf samples, we now describe a new species of pycnophyid kinorhynch, Fujuriphyes viserioni sp. ...
Fujuriphyes viserioni sp. nov. is described from the Gulf of Mexico. The new species is characterized by the scarcity of laterodorsal setae, and the abundance of ventrolateral setae, which are present on segments 1, 3–8, and 10, with two pairs on segment 5 and one pair on the remaining segments. Moreover, Fujuriphyes viserioni sp. nov. is recognized by the general absence of middorsal specializations along the trunk and the lack of ventral tubes on segment 2 in males. Type material of Leiocanthus langi (Higgins, 1964) and L. fimbriatus (Higgins, 1982) and additional specimens of L. langi collected from the Gulf of Mexico were furthermore studied in detail. Their examination revealed that L. fimbriatus is a junior synonym of L. langi, a species with an unusually high intraspecific variation in its morphology. Identification keys to all known species of Fujuriphyes and Leiocanthus are provided together with emended diagnoses for both genera.
