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Lucernariopsis capensis Carlgren. A, B, C. General views of the preserved specimen from Itanhaém, Brazil. D. Gonad (gd) and gastric cirri (gc). E. Two arms, with cushion or pad-like organ, tentacular cluster, and a probable vestige of primary tentacle. F. Base of stalk, with a central pit. G. Isorhiza of tentacle. H. Eurytele (type I) of tentacle. I. Eurytele (type II) of subumbrellar vesicles. J. Eurytele (type III) of subumbrellar vesicles. K. Isorhiza of subumbrellar vesicles. Scale: A-F: 0.6 mm; G-K: 5.0 µm. am-arm; bd-basal disc of stalk; cl-calyx; pd-pad-like adhesive organ; pr-primary tentacle; pt-pit; sc-secondary tentacle; sk-stalk; tc-tentacular cluster.
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Staurozoa is a class of Cnidaria comprising stalked, benthic jellyfishes (Marques & Collins 2004) that encompasses about 51 species (Mills 1999; Zagal et al. 2011). Stauromedusae are distributed worldwide, but are more common in temperate and polar waters (Mills & Hirano 2007). Taxonomic knowledge of these cnidarians is inadequate, as is informatio...
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... its green color in formalin (Carlgren 1938) so was probably collected a short time before being sent to him. Material examined. Itanhaém, São Paulo, Brazil, Atlantic Ocean, ~24°11'30''S; 46°47'30''W. 08 April 1985, intertidal zone, on algae (Sargassum sp.), formaldehyde solution, col. M.A. Haddad, det. L.S. Miranda and C.E. Mills, 1 individual ( Fig. 1), MZUSP 1566. The material is not well preserved, making it difficult to observe some structures (e.g., gonads, inner part of stalk, and ...
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... Calyx (umbrella) pyramidal, narrowing aborally, height 3.34 mm (excluding arms and tentacular clusters), maximum width 3.25 mm; calyx separated from stalk ( Fig. 1A−C). Eight adradial arms, length 0.28 mm, width 0.39 mm (excluding tentacular clusters) (Fig. 1A, B, E). Arms paired, maximum distance between arms (between base of tentacular cluster) 1.09 mm, minimum distance 0.76 mm. Distal region of each arm with 11−15 capitate tentacles. Tentacles morphologically similar, varied in length (Fig. 1E); ...
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... Calyx (umbrella) pyramidal, narrowing aborally, height 3.34 mm (excluding arms and tentacular clusters), maximum width 3.25 mm; calyx separated from stalk ( Fig. 1A−C). Eight adradial arms, length 0.28 mm, width 0.39 mm (excluding tentacular clusters) (Fig. 1A, B, E). Arms paired, maximum distance between arms (between base of tentacular cluster) 1.09 mm, minimum distance 0.76 mm. Distal region of each arm with 11−15 capitate tentacles. Tentacles morphologically similar, varied in length (Fig. 1E); each tentacle with hollow stem and distal globular end covered with nematocysts. Anchors lacking, ...
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... from stalk ( Fig. 1A−C). Eight adradial arms, length 0.28 mm, width 0.39 mm (excluding tentacular clusters) (Fig. 1A, B, E). Arms paired, maximum distance between arms (between base of tentacular cluster) 1.09 mm, minimum distance 0.76 mm. Distal region of each arm with 11−15 capitate tentacles. Tentacles morphologically similar, varied in length (Fig. 1E); each tentacle with hollow stem and distal globular end covered with nematocysts. Anchors lacking, except one small globular knob between two of the arms, which is probably a vestigial primary tentacle (Fig. 1E). Aboral stalk morphologically distinct from calyx, with one internal chamber at median region (no histological details at ...
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... minimum distance 0.76 mm. Distal region of each arm with 11−15 capitate tentacles. Tentacles morphologically similar, varied in length (Fig. 1E); each tentacle with hollow stem and distal globular end covered with nematocysts. Anchors lacking, except one small globular knob between two of the arms, which is probably a vestigial primary tentacle (Fig. 1E). Aboral stalk morphologically distinct from calyx, with one internal chamber at median region (no histological details at base of stalk), without muscles; length 3.10 mm, diameter 1.17 mm, diameter of base of stalk (swollen adhesive disc) 1.82 mm (Fig. 1A−C). Base of stalk with an ovoid pit, 0.35 x 0.20 mm (Fig. 1F). Abaxial cushion ...
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... small globular knob between two of the arms, which is probably a vestigial primary tentacle (Fig. 1E). Aboral stalk morphologically distinct from calyx, with one internal chamber at median region (no histological details at base of stalk), without muscles; length 3.10 mm, diameter 1.17 mm, diameter of base of stalk (swollen adhesive disc) 1.82 mm (Fig. 1A−C). Base of stalk with an ovoid pit, 0.35 x 0.20 mm (Fig. 1F). Abaxial cushion or pad-like adhesive organ at base of tentacular cluster, length 0.13 mm, width 0.60 mm (Fig. 1A, E). Manubrium four-sided in cross-section. Numerous gastric cirri in gastrovascular cavity (Fig. 1D). Eight adradial gonads extending from manubrium to distal end ...
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... a vestigial primary tentacle (Fig. 1E). Aboral stalk morphologically distinct from calyx, with one internal chamber at median region (no histological details at base of stalk), without muscles; length 3.10 mm, diameter 1.17 mm, diameter of base of stalk (swollen adhesive disc) 1.82 mm (Fig. 1A−C). Base of stalk with an ovoid pit, 0.35 x 0.20 mm (Fig. 1F). Abaxial cushion or pad-like adhesive organ at base of tentacular cluster, length 0.13 mm, width 0.60 mm (Fig. 1A, E). Manubrium four-sided in cross-section. Numerous gastric cirri in gastrovascular cavity (Fig. 1D). Eight adradial gonads extending from manubrium to distal end of arms, organized into four pairs of bands; each band ...
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... at median region (no histological details at base of stalk), without muscles; length 3.10 mm, diameter 1.17 mm, diameter of base of stalk (swollen adhesive disc) 1.82 mm (Fig. 1A−C). Base of stalk with an ovoid pit, 0.35 x 0.20 mm (Fig. 1F). Abaxial cushion or pad-like adhesive organ at base of tentacular cluster, length 0.13 mm, width 0.60 mm (Fig. 1A, E). Manubrium four-sided in cross-section. Numerous gastric cirri in gastrovascular cavity (Fig. 1D). Eight adradial gonads extending from manubrium to distal end of arms, organized into four pairs of bands; each band consisting of elongated, nodular lobes of irregular shape (Fig. 1D). Numerous nematocyst vesicles distributed at margin on ...
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... 1.17 mm, diameter of base of stalk (swollen adhesive disc) 1.82 mm (Fig. 1A−C). Base of stalk with an ovoid pit, 0.35 x 0.20 mm (Fig. 1F). Abaxial cushion or pad-like adhesive organ at base of tentacular cluster, length 0.13 mm, width 0.60 mm (Fig. 1A, E). Manubrium four-sided in cross-section. Numerous gastric cirri in gastrovascular cavity (Fig. 1D). Eight adradial gonads extending from manubrium to distal end of arms, organized into four pairs of bands; each band consisting of elongated, nodular lobes of irregular shape (Fig. 1D). Numerous nematocyst vesicles distributed at margin on subumbrellar surface. Preserved material yellowish-brown in color. Tentacles with two types of ...
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... at base of tentacular cluster, length 0.13 mm, width 0.60 mm (Fig. 1A, E). Manubrium four-sided in cross-section. Numerous gastric cirri in gastrovascular cavity (Fig. 1D). Eight adradial gonads extending from manubrium to distal end of arms, organized into four pairs of bands; each band consisting of elongated, nodular lobes of irregular shape (Fig. 1D). Numerous nematocyst vesicles distributed at margin on subumbrellar surface. Preserved material yellowish-brown in color. Tentacles with two types of nematocysts: isorhizas (light microscopy was insufficient to distinguish spines), abundant, 11.74 x 2.56 µm (n=10) (mean size of undischarged capsules); euryteles (type I), scarce, 11.0 ...
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... nematocyst vesicles distributed at margin on subumbrellar surface. Preserved material yellowish-brown in color. Tentacles with two types of nematocysts: isorhizas (light microscopy was insufficient to distinguish spines), abundant, 11.74 x 2.56 µm (n=10) (mean size of undischarged capsules); euryteles (type I), scarce, 11.0 x 6.0 µm (n=1) (Fig. 1G, H). Subumbrellar vesicles with three types of nematocysts: isorhizas (light microscopy was insufficient to distinguish spines), scarce, 10.57 (Fig. 1I−K). pr-primary tentacle; pt-pit; sc-secondary tentacle; sk-stalk; tc-tentacular ...
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... isorhizas (light microscopy was insufficient to distinguish spines), abundant, 11.74 x 2.56 µm (n=10) (mean size of undischarged capsules); euryteles (type I), scarce, 11.0 x 6.0 µm (n=1) (Fig. 1G, H). Subumbrellar vesicles with three types of nematocysts: isorhizas (light microscopy was insufficient to distinguish spines), scarce, 10.57 (Fig. 1I−K). pr-primary tentacle; pt-pit; sc-secondary tentacle; sk-stalk; tc-tentacular ...
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... its type-locality. The morphology of Brazilian material matches the original description as presented by Carlgren (1938) from the South African type. However, the specimen from Brazil is smaller (Table 1) and perhaps a juvenile, as corroborated by the probable vestige of a primary tentacle found between two of the arms (see Corbin 1978, p. 285) (Fig. ...
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... in the gastric pouch, with several attached nodular lobes, rather irregular in shape, similar to L. capensis ( Zagal et al. 2011); 4) the Antarctic Lucernariopsis vanhoeffeni (Browne) (Fig. 2), 32-137 m depth, on rocks, with a smaller stalk, pad-like adhesive organ on the distal arm tentacles, different from the pad on the arms of L. capensis (Fig. 1E), and gonads embedded in the gastric pouch (Browne 1910;Zagal et al. 2011; Smithsonian online ...
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... Roundish rhopaloids were present in H. tenuis and C. convolvulus and appeared in high abundances in the white spots but were not present in any body part of H. auricula specimens which lacked white spots. Roundish rhopaloids in the white spots were also documented for other staurozoans (Miranda et al. 2012b(Miranda et al. , 2017, and it is likely that roundish rhopaloids are only present in species with white nematocyst spots. Some studies indicate that the white nematocyst spots can also contain oval rhopaloids (e.g., Larson 1988;Miranda et al. 2012b). ...
... Roundish rhopaloids in the white spots were also documented for other staurozoans (Miranda et al. 2012b(Miranda et al. , 2017, and it is likely that roundish rhopaloids are only present in species with white nematocyst spots. Some studies indicate that the white nematocyst spots can also contain oval rhopaloids (e.g., Larson 1988;Miranda et al. 2012b). Histological sections on various staurozoan species revealed a region of nematocyst formation at the peripheral region of white spots (Miranda et al. 2016a). ...
Scientific knowledge and records on staurozoans are limited probably because of their inconspicuous life habit and the small number of specialists for this taxon. To increase the awareness for Staurozoa, we identified morphological and molecular features of the three staurozoan species Haliclystus tenuis Kishinouye, 1910, Haliclystus auricula Clark, 1863, and Craterolophus convolvulus (Johnston, 1835) collected on the coast of the island Helgoland to evaluate their suitability as diagnostic characters. Useful macromorphological diagnostic features were the patterns of white spots of nematocysts and internal arm structures, whereas tentacle and gonad follicle numbers showed high intraspecific variations. Morphometric measurements on photographs of living specimens provided reliable data for interspecific comparisons. Comprehensive nematocyst analyses revealed interspecific shape differences of isorhizas and three types of rhopaloids, indicating that the staurozoan cnidome is more diverse than previously assumed. However, the taxonomic value of nematocyst analyses in Staurozoa remains unclear because comprehensive data is still lacking for most species. Comparative molecular genetic sequence analyses of mitochondrial 16S and cytochrome c oxidase subunit I (COI) and nuclear 18S ribosomal DNA identified the three species and confirmed their morphological identification. In comparison to published data, our analyses indicate similarities between H. auricula and Haliclystus antarcticus Pfeffer, 1889. Proteomic fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) differentiated all three species, suggesting that this technique could provide an alternative rapid identification method for staurozoans.
... Zagal (2004a) reported that different factors should be considered in evaluating habitat selection of stalked jellyfishes, including pollution. Miranda et al. (2012b) proposed that specimens of Calvadosia capensis were never found again on the Southern coast of São Paulo (Brazil) because of the Bgradual pollution and environmental decay^along the region. In addition, Miranda and Marques (2016) discussed the possible influence of a dam collapse on populations of Calvadosia corbini in Espírito Santo, Brazil. ...
In this review, we present the current state of biodiversity knowledge for the class Staurozoa (Cnidaria), including richness estimates, geographical and bathymetric distributions, substrate use, feeding, behavior, life cycle, and conservation. Based on non-parametric, statistical incidence estimators, the global inventory of 50 known and accepted species of stalked jellyfishes might be regarded as close to complete, but we discuss possible bias related to the lower research effort applied in the Southern Hemisphere. Most of the species occur at mid-latitudes, presenting a distributional pattern that disagrees with the classic pattern of diversity (higher richness near the Equator). Specimens are frequently found on algae, but they have also been reported attached to rocks, seagrasses, shells, mud, sand, coral/gorgonian, sea cucumber, and serpulid tube. Most of the species are found in the intertidal and shallow subtidal regions, but species of Lucernaria have been reported at more than 3000 m deep. Amphipods and copepods are the prey items most frequently reported, and stauromedusae have been observed being actively preyed upon by nudibranch mollusks and pycnogonids. Apparently, stalked jellyfishes have a high sensitivity to anthropic impacts in the environment, and promotion of the class, one of the least studied among Cnidaria, is perhaps the best possible conservation strategy.
... The taxonomic classification follows Miranda et al. (2016b). The species accounts are based on our observations of freshly collected material and on previous literature descriptions, except for C. capensis, which we were unable to re-collect, and relied exclusively on published information from both South Africa (Carlgren 1938) and Brazil (Miranda et al. 2012b). Specimens of C. tasmaniensis and C. corbini (Table 2) were also examined for morphological comparison with the South African material. ...
... This species is closely related to C. tasmaniensis and C. corbini, in a clade whose possible synapomorphy is a broad pad-like adhesive structure on the tip of each arm (Miranda et al. 2016b). This feature is also present in C. hawaiiensis (Edmondson 1930;Grohmann et al. 1999) and in C. capensis (Carlgren 1938;Miranda et al. 2012b), suggesting that they too may belong to this clade (Miranda et al. 2016b). Calvadosia cruxmelitensis has a slightly different pad-like adhesive structure on the tip of the arm, in which the secondary tentacles arise directly from this structure (Corbin 1978;Miranda et al. 2016b). ...
... In addition, Carlgren (1938) prepared histological sections from this material and one slide is deposited in the Invertebrates Collection of the Swedish Museum of Natural History, catalog number NRM:EVmain:115053 (GBIF ID 1099397008). A second individual was recorded from Brazil and is deposited in the Museum of Zoology of the University of São Paulo, Brazil, catalog number MZUSP 1566 (Miranda et al. 2012b). To date the species is known only from these preserved specimens and it has never been seen or photographed alive, despite attempts to collect the species on April 7-8 th , 2016, in tidal pools on the rock shore in East London (type locality) and Gunube (about 10km east of East London). ...
Stalked jellyfishes (Cnidaria: Staurozoa) are cryptic, benthic animals, known mainly from polar and temperate waters of the Northern Hemisphere. We describe a new species, Calvadosia lewisi, from South Africa and review the staurozoan fauna of the region. Three other species are previously known from South Africa: Calvadosia capensis (Carlgren, 1938); Depastromorpha africana Carlgren, 1935; and Lipkea stephensoni Carlgren, 1933, but all of these are known from very few records and have been poorly illustrated and documented to date. We provide brief descriptions and photographic illustrations for each species and a list of local and global geographical records. Two (L. stephensoni and C. lewisi), but possibly three (D. africana), of the four known South African staurozoan species are endemic from South Africa. The new species, images, and extra distributional records presented here greatly improve knowledge of the staurozoan fauna in South Africa and, consequently, of the Southern Hemisphere.
... However, the presence of four chambers only at the base of the peduncle is not easy to observe, demanding serial transversal sections of a wellpreserved and straight peduncle (the bodies of stauromedusae frequently contract during preservation). Indeed, cross sections at the bases of peduncles are rare in the descriptions of species, and most of them include only information about the median region of the peduncle (Edmondson, 1930;Carlgren, 1938;Miranda et al., 2012). Consequently, it is difficult to be sure that this distinction was correctly applied in former determinations. ...
... Pad-like structures can be present individually in the outermost secondary tentacles of the tentacular cluster (Larson & Fautin, 1989), or as a broad structure on the tip of each arm (Fig. 24;Larson, 1980;Miranda et al., 2012). We found individual pad-like adhesive structures in the outermost secondary tentacles in C. convolvulus, M. uchidai, C. cruciformis, and C. vanhoeffeni. ...
Comparative efforts to understand the body plan evolution of stalked jellyfishes are scarce. Most characters, and particularly internal anatomy, have neither been explored for the class Staurozoa, nor broadly applied in its taxonomy and classification. Recently, a molecular phylogenetic hypothesis was derived for Staurozoa, allowing for the first broad histological comparative study of staurozoan taxa. This study uses comparative histology to describe the body plans of nine staurozoan species, inferring functional and evolutionary aspects of internal morphology based on the current phylogeny of Staurozoa. We document rarely-studied structures, such as ostia between radial pockets, intertentacular lobules, gametoducts, pad-like adhesive structures, and white spots of nematocysts (the last four newly proposed putative synapomorphies for Staurozoa). Two different regions of nematogenesis are documented. This work falsifies the view that the peduncle region of stauromedusae only retains polypoid characters; metamorphosis from stauropolyp to stauromedusa occurs both at the apical region (calyx) and basal region (peduncle). Intertentacular lobules, observed previously in only a small number of species, are shown to be widespread. Similarly, gametoducts were documented in all analyzed genera, both in males and females, thereby elucidating gamete release. Finally, ostia connecting adjacent gastric radial pockets appear to be universal for Staurozoa. Detailed histological studies of medusozoan polyps and medusae are necessary to further understand the relationships between staurozoan features and those of other medusozoan cnidarians.
... The only other staurozoan known on our coast, Lucernariopsis capensis Carlgren 1938, was recorded only once, at Itanhaém, State of São Paulo (SP) (Figure 1f), in 1985 (Miranda et al. 2012). This fact could be related to the increasing pollution of the southern coast of SP (Miranda et al. 2012), since staurozoan populations seem to be vulnerable to anthropic impacts. ...
... The only other staurozoan known on our coast, Lucernariopsis capensis Carlgren 1938, was recorded only once, at Itanhaém, State of São Paulo (SP) (Figure 1f), in 1985 (Miranda et al. 2012). This fact could be related to the increasing pollution of the southern coast of SP (Miranda et al. 2012), since staurozoan populations seem to be vulnerable to anthropic impacts. For instance, once locally abundant populations of Haliclystus auricula Clark 1863 have now disappeared, probably due to contamination and pollution of their habitat (Mayer 1910, Berrill 1962. ...
O colapso da barragem de rejeitos de Fundão, em Mariana (Minas Gerais, Brasil) iniciou uma enorme tragédia humana e, provavelmente, o mais grave desastre ambiental da história recente do Brasil. A barragem continha rejeitos do processamento de minério de ferro de minas de propriedade da Samarco, uma empresa controlada pela brasileira Vale S.A. e pela anglo-australiana BHP Billiton Ltda. Apesar de tentativas ineficazes para conter o desastre, após 16 dias a lama atingiu o mar, onde provavelmente afetará milhares de espécies da fauna e flora marinhas. Este ponto de vista fornece um exemplo de uma dessas espécies, o cnidário Kishinouyea corbini Larson 1980 (Staurozoa), emblemática pois é extremamente rara, insuficientemente estudada e sua distribuição conhecida para a costa brasileira sobrepõe a área ameaçada pelo desastre. Com base neste caso, discutimos a necessidade de esforços para monitorar e minimizar os possíveis impactos desse crime socioambiental, bem como para identificar e punir todos os responsáveis por esta tragédia, incluindo agências estatais de fiscalização e licenciamento negligentes, a fim de evitar futuras tragédias semelhantes.
... Hirano, 1986). Additionally, a cross-section at the very base of the peduncle is rarely reported in the description of species; most only include information concerning the middle region of the peduncle (e.g., Kishinouyea hawaiiensis in Edmondson, 1930;Lucernariopsis capensis in Carlgren, 1938;Miranda et al., 2012), or do not mention where the peduncle was sectioned (e. g., Corbin, 1978), causing some doubt about whether this distinction is reliable in defining these genera. Recently, Lucernariopsis tasmaniensis was described with "a single cruciform chamber that becomes four-chambered basally within pedal disc" (Zagal et al., 2011), a character that corresponds to the genera Kishinouyea and Sasakiella (Kramp, 1961). ...
... Pad-like structures can be present individually in the outermost secondary tentacles of the tentacular cluster (Larson & Fautin, 1989), or as a broad structure on the tip of each arm (Larson, 1980;Miranda et al., 2012) (Fig. 15; Table 8). Apparently, the pads help the animal to adhere to its substrate. ...
Staurozoan classification is highly subjective, based on phylogeny-free inferences, and suborders, families, and genera are commonly defined by homoplasies. Additionally, many characters used in the taxonomy of the group have ontogenetic and intraspecific variation, and demand new and consistent assessments to establish their correct homologies. Consequently, Staurozoa is in need of a thorough systematic revision. The aim of this study is to propose a comprehensive phylogenetic hypothesis for Staurozoa, providing the first phylogenetic classification for the group. According to our working hypothesis based on a combined set of molecular data (mitochondrial markers COI and 16S, and nuclear markers ITS, 18S, and 28S), the traditional suborders Cleistocarpida (animals with claustrum) and Eleutherocarpida (animals without claustrum) are not monophyletic. Instead, our results show that staurozoans are divided into two groups, herein named Amyostaurida and Myostaurida, which can be distinguished by the absence/presence of interradial longitudinal muscles in the peduncle, respectively. We propose a taxonomic revision at the family and genus levels that preserves the monophyly of taxa. We provide a key for staurozoan genera and discuss the evolution of the main characters used in staurozoan taxonomy.
... The geographic discontinuity in distribution, assumed by Farrapeira et al. (2011) to infer the introduced status of a species, may be actually caused by many reasons other than introductions. The first reason is that this may be the natural distribution of the species, derived from historical geological reasons (e.g., Miranda et al., 2012) or from idiosyncrasies of its natural history (e.g., , such as ecology and succession of the community, or dispersal capabilities by rafting (Thiel and Gutow, 2005). For instance, the tanaid Hexapleomera robusta, considered to be cryptogenic by Farrapeira et al. (2011 , Table 1) is widely distributed because of its commensal association with turtles and manatees (Morales-Vela et al., 2008), with no need of human mediated transport. ...
The Brazilian Ministry of the Environment organized in
2004–2005 a national program to evaluate the existing information
on invasive species in terrestrial and aquatic biomes. A list
of 58 exotic species of planktonic and benthic invertebrates, fish,
macroalgae, and phytoplankton, updated till late 2008, was generated
in a marine ecosystem assessment study carried out by a
group of 14 specialists, including three invited reviewers (Lopes,
2009). The study made use of a conservative approach by only
including species with well-supported evidence of introduction,
based on established criteria (e.g., Chapman and Carlton, 1991).
Evidently, lists of exotic or introduced species need to be accurate
because they shall serve as fundamental elements for public conservation policies, influencing economic and social stakeholders.
Periodic re-assessment of such validated lists is clearly necessary,
but the same concern and criteria followed by Lopes (2009) shall
be applied unless new arguments or data demonstrate incorrectness
or caveats in his approach.
Cilia are widely present in metazoans and have various sensory and motor functions, including collection of particles through feeding currents in suspensivorous animals. Suspended particles occur at low densities and are too small to be captured individually, and therefore must be concentrated. Animals that feed on these particles have developed different mechanisms to encounter and capture their food. These mechanisms occur in three phases: (i) encounter; (ii) capture; and (iii) particle handling, which occurs by means of a cilia-generated current or the movement of capturing structures (e.g. tentacles) that transport the particle to the mouth. Cilia may be involved in any of these phases. Some cnidarians, as do other suspensivorous animals, utilise cilia in their feeding mechanisms. However, few studies have considered ciliary flow when examining the biomechanics of cnidarian feeding. Anthozoans (sessile cnidarians) are known to possess flow-promoting cilia, but these are absent in medusae. The traditional view is that jellyfish capture prey only by means of nematocysts (stinging structures) and mucus, and do not possess cilia that collect suspended particles. Herein, we first provide an overview of suspension feeding in invertebrates, and then critically analyse the presence, distribution, and function of cilia in the Cnidaria (mainly Medusozoa), with a focus on particle collection (suspension feeding). We analyse the different mechanisms of suspension feeding and sort them according to our proposed classification framework. We present a scheme for the phases of pelagic jellyfish suspension feeding based on this classification. There is evidence that cilia create currents but act only in phases 1 and 3 of suspension feeding in medusozoans. Research suggests that some scyphomedusae must exploit other nutritional sources besides prey captured by nematocysts and mucus, since the resources provided by this diet alone are insufficient to meet their energy requirements. Therefore, smaller particles and prey may be captured through other phase-2 mechanisms that could involve ciliary currents. We hypothesise that medusae, besides capturing prey by nematocysts (present in the tentacles and oral arms), also capture small particles with their cilia, therefore expanding their trophic niche and suggesting reinterpretation of the trophic role of medusoid cnidarians as exclusively plankton predators. We suggest further study of particle collection by ciliary action and its influence on the biomechanics of jellyfishes, to expand our understanding of the ecology of this group.
