Figure 1 - uploaded by Carlos J. Moura
Content may be subject to copyright.
Examples of Plumularioidea hydroids: (a) Aglaophenia cf. pluma-Aglaopheniidae; (b) Halopteris sp.-Halopterididae; (c) Kirchenpaueria pinnata-Kirchenpaueriidae; (d) Dentitheca dendritica-Plumulariidae. Credits: Carlos J. Moura.
Source publication
Marine hydroids are important benthic components of shallow and deep waters worldwide, but their taxonomy is controversial because diagnostic morphological characters to categorize taxa are limited. Their genetic relationships are also little investigated. We tested taxonomic hypotheses within the highly speciose superfamily Plumularioidea by integ...
Contexts in source publication
Context 1
... However, the morphological resemblance or divergence noticed between vouchers of each clade was also considered. We further provided degrees of uncertainty to the species delimitation results taking into account knowledge of the morphological diversity of lineages, and the probabili- ties output from the PTP analyses (Supplementary Table S1 and Fig. ...
Context 2
... evaluated phylogenetic relationships among 1,114 16S sequences of distinct Plumularioidea colonies, and obtained 676 unique haplotypes. Figure 3 and Supplementary Fig. S1 present a phylogenetic reconstruction of Plumularioidea haplotypes as inferred from 16S sequence data. ...
Context 3
... obtained mostly similar results (differences noted in the following subsections) between the phyloge- netic hypotheses generated by the alignments with combined 16S and COI sequence data ( Fig. 4; Supplementary Fig. S2) and the alignments with only 16S sequence data ( Fig. 3; Supplementary Fig. S1). Additionally, we found a high level of coherence between morphological and molecular divergences of taxa. ...
Context 4
... the present results disagree partially with some of these conclusions. First, Kirchenpaueria bonnevieae, a species thought to belong to the family Kirchenpaueriidae, clusters within the family Plumulariidae. Additionally, Pseudoplumularia marocana, classified as a member of Plumulariidae, clusters inside the family Halopterididae (Supplementary Fig. S1; Fig. 3). Therefore, the families Kirchenpaueriidae and Plumulariidae are polyphyletic and the family Halopterididae paraphyletic unless other taxonomic changes are ...
Context 5
... addition, Pseudoplumaria also resembles morphologically the halopteridid genus Polyplumaria 47 (pers. obs.), which is its sister group in the 16S phylogeny ( Fig. 3; Supplementary Fig. S1). ...
Context 6
... nodal support is not indicated, all phylogenetic analyses achieved 95-100% of nodal support. See detailed composition of branches in Supplementary Fig. S1. (Figs 3 and 4) suggest that this taxon may cluster within Kirchenpaueriidae. ...
Context 7
... relations among genera. The great majority of the Plumularioidea genera repre- sented in our analyses are polyphyletic (Figs 3 and 4; Supplementary Figs S1 and S2). Of the 21 nominal gen- era represented in our analyses, we recovered only nine monophyletic taxa, namely: Taxella and Gymnangium (Aglaopheniidae); Schizotricha (Schizotrichidae); Oswaldella and Pycnotheca (Kirchenpaueriidae); Polyplumaria and Pseudoplumaria (Halopterididae); Nemertesia and Monotheca (Plumulariidae). ...
Context 8
... Polyplumaria and Pseudoplumaria (Halopterididae); Nemertesia and Monotheca (Plumulariidae). The genus Gymnangium was previously reported to be polyphyletic 6,18,23,25 . Consequently the genus Taxella was resurrected 25 to provide monophyly to the genus Gymnangium (Fig. 3). The remaining genera appearing as monophyletic in our analyses ( Fig. 3; Supplementary Fig. S1) are represented by only one (in which case monophyly was not tested) or only a few species. The COI+16S phylogenetic hypotheses ( Fig. 4; Supplementary Fig. S2) confirmed polyphyly of genera of the Aglaopheniidae (Cladocarpus, Lytocarpia, Macrorhynchia, Aglaophenia), Plumulariidae (Plumularia) and Halopterididae (Halopteris and ...
Context 9
... Aglaopheniidae. Five of the seven nominal genera of the Aglaopheniidae, namely: Aglaophenia, Lytocarpia, Macrorhynchia, Aglaophenopsis, Cladocarpus and Streptocaulus, are not monophyletic ( Supplementary Fig. S1). Uniquely the genera Taxella and Gymnangium are monophyletic (Supplementary Fig. S1; see above). ...
Context 10
... of the seven nominal genera of the Aglaopheniidae, namely: Aglaophenia, Lytocarpia, Macrorhynchia, Aglaophenopsis, Cladocarpus and Streptocaulus, are not monophyletic ( Supplementary Fig. S1). Uniquely the genera Taxella and Gymnangium are monophyletic (Supplementary Fig. S1; see above). This finding supports that the morphology of the reproductive structures 34 alone fails to be diagnostic of the Aglaopheniidae. ...
Context 11
... A. rhynchocarpa, A. cupressina and possibly A. postdentata. The phylogenetic associations of the first two species were mentioned above. While the phylogenetic placement of A. rhynchocarpa, A. cupressina and A. postdentata are somewhat uncertain with 16S data, these species do not cluster with the other Aglaophenia species represented ( Fig. 3; Supplementary Fig. S1). Supplementary Fig. S2 further highlights the clustering of A. rhynchocarpa with Lytocarpia myriophyllum, and of L. brevirostris with A. ...
Context 12
... include the following taxa: clade (1) Streptocaulus species plus Cladocarpus bocki; clade (2) Gymnangium species; clade (3) Aglaophenopsis and Cladocarpus species (excluding C. bocki); clade (4) Aglaophenia, Macrorhynchia, Lytocarpia and Taxella species. "Clade 1" seems the outgroup to all the other Aglaopheniidae represented; "clade 2" may be sister to a cluster containing "clade 3" and "clade 4" (Figs 3 and 4; Supplementary Figs S1 and S2). One could interpret these four main clades as distinct genera, a decision that would simplify the confusion related to the taxonomic categorizations in this family 28,47,[49][50][51][52][53][54] . ...
Context 13
... profunda, a species collected from deep waters off Florida, was recovered as sister to a clade containing close haplotypes of Antarctic Schizotricha species. Despite the reasonably high genetic divergence ("P" distance of 15-22%) between these clades, the genus Schizotricha is monophyletic (Supplementary Fig. S1). ...
Context 14
... nominal genera of the Kirchenpaeuriidae s.l. are represented in the present data: Kirchenpaueria, Pycnotheca,Oswaldella and Plumalecium. Of these, the genus Kirchenpaueria is shown to be polyphyletic (Figs 3 and 4; Supplementary Figs S1 and S2). ...
Context 15
... recovered three main clades of Kirchenpaueria s.l. (Fig. 3; Supplementary Fig S1), which could provide the basis for establishing distinct genera. "Kirchenpaueria" bonnevieae, as already noted, belongs to the Plumulariidae. The clade containing Kirchenpaueria pinnata (the type species of the genus) and the possible conspecific K. similis (Moura et al. 6 ; present study), without doubt corresponds to the genus ...
Context 16
... (cf.) plumu- larioides, a species until recently considered as a member of the genus Kirchenpaueria, together with haplotypes of the genus Oswaldella form a clade sister to a branch containing Pycnotheca mirabilis and Kirchenpaueria pin- nata. The sister group to these Kirchenpaueriidae taxa is Kirchenpaueria halecioides (Supplementary Fig. S1). Kirchenpaueria halecioides is actually the type species of the genus Ventromma (Stechow) 55 , to which this species has been sometimes assigned until recently 33,34,56 . ...
Context 17
... resurrection of that genus, therefore, would seem well advised. However, Plumalecium plumularioides presents the diagnostic characters of the genus Ventromma 34 , but clusters in a divergent clade as a sister group to specimens of Oswaldella (Supplementary Fig. S1). Family Halopterididae. ...
Context 18
... Halopterididae. Antennella, Halopteris and Monostaechas, the most speciose genera of the fam- ily Halopterididae 34 , are clearly polyphyletic (Figs 3 and 4; Supplementary Figs S1 and S2). The genera Pseudoplumaria and Polyplumaria are only represented by a single nominal species. ...
Context 19
... to the growth form of colonies 31 , however, that criterion clearly fails to be diagnostic of natural groups within Halopterididae. Three well-supported main clades are recovered within the Halopterididae (Figs 3 and 4; Supplementary Figs S1 and S2). One clade comprises Pseudoplumaria and Polyplumaria, which are genetically close sister groups ( Fig. 3; Supplementary Fig. S1; 0.7-2.6% of "P" distance) sharing many morphological similarities 47 (pers. obs.). Another main clade, possibly sister to the previously mentioned relationship (albeit without great nodal support in some analyses), includes the nominal species Antennella "secundaria" ("lineage 1"), Halopteris minuta, H. schucherti, H. violae, H. ...
Context 20
... Another main clade, possibly sister to the previously mentioned relationship (albeit without great nodal support in some analyses), includes the nominal species Antennella "secundaria" ("lineage 1"), Halopteris minuta, H. schucherti, H. violae, H. diaphana and H. tenella ( Supplementary Figs S1 and S2). The third main branch of the Halopterididae includes other taxa identifiable as belonging to three nominal genera that are not monophyletic: Halopteris (nominal species: H ...
Context 21
... Monostaechas (nominal species: M. quadridens) ( Supplementary Figs S1 and S2). Complementing analyses ( Supplementary Fig. S1), further suggest that within the "third main branch", the clade containing Halopteris sp., H. vervoorti, H. sibogae, H. alternata, H. carinata and H. liechterniii, is sister to a clade containing A. secundaria (lineages 2-11), M. quadridens, A. confusa, A. similis, H. geminata and H. catharina. ...
Context 22
... Monostaechas (nominal species: M. quadridens) ( Supplementary Figs S1 and S2). Complementing analyses ( Supplementary Fig. S1), further suggest that within the "third main branch", the clade containing Halopteris sp., H. vervoorti, H. sibogae, H. alternata, H. carinata and H. liechterniii, is sister to a clade containing A. secundaria (lineages 2-11), M. quadridens, A. confusa, A. similis, H. geminata and H. catharina. ...
Context 23
... Plumulariidae. Two of the four nominal genera of Plumulariidae, namely Plumularia (Figs 3 and 4; Supplementary Figs S1 and S2) and Dentitheca ( Fig. 3; Supplementary Fig. S1), were not shown to be monophy- letic. The genera Nemertesia and Monotheca are so far verified as monophyletic (Figs 3 and 4; Supplementary Figs S1 and S2). However, we note that the Monotheca is not always considered a valid taxon and these species are often classified as Plumularia (e.g., WoRMS 27 ...
Context 24
... clade corresponding to the true genus Plumularia contains the nominal species Plumularia setacea (the type species of the genus), P. strictocarpa, P. virginiae, P. duseni, P. lagenifera, P. gaimardi, P. warreni, P. setaceoides, P. filicaulis and P. cf. hyalina (which has morphological similarities with the genus Monotheca; see Watson 57 ). It is not clear whether this "true Plumularia" clade is sister to a clade containing the genus Nemertesia or instead is sister to an evolutionary branch (possibly representing a cryptic genus) containing the nominal spe- cies Plumularia mooreana, P. floridana and P. sinuosa ( Supplementary Figs S1 and S2). ...
Context 25
... results reveal the genus Dentitheca to be paraphyletic ( Fig. 3; Supplementary Fig. S1) due to its inclu- sion amidst "Plumularia" species, namely "Plumularia" habereri, "Plumularia elongata and "Plumularia" spi- ralis. Although "P". habereri and "P. elongata" have been occasionally considered as belonging to the genus Dentitheca 58,59 , "P." spiralis has been unequivocally assigned to the genus Plumularia 60 . Thus, the ...
Context 26
... genus Monotheca was recovered as monophyletic and appears to be the outgroup of the remain- ing Plumulariidae ( Fig. 3; Supplementary Fig. S1). We included only four of the twelve recognized species of Monotheca, and therefore, cannot exclude the possibility that the morphologically diagnostic characters of this genus may not be valid (see Watson 57 ). If we consider the represented haplotype of "Plumularia cf. hyalina" as a Monotheca species, the genus would be ...
Context 27
... the represented haplotype of "Plumularia cf. hyalina" as a Monotheca species, the genus would be polyphyletic. Although we did side with the arguments of Watson 57 and accepted that New Zealand material does not correspond to Monotheca hyalina, nor to the genus Monotheca. Nevertheless, due to the genetic distinctiveness of the Monotheca clade ( Fig. 3; Supplementary Fig. S1), that includes its type species -M. margaretta, we recommend revalidation of the genus ...
Context 28
... Delimitation Analyses. After the combination and interpretation of the species delimitation anal- yses undertaken, we propose 198 species of Plumularioidea hydroids (Supplementary Table S1, Supplementary Fig. S1). This number contrasts with the 123 nominal species plus the 17 unknown morphological species that we considered during the collection stage of this study. ...
Context 29
... number contrasts with the 123 nominal species plus the 17 unknown morphological species that we considered during the collection stage of this study. We have high confidence for the species delimitation of 125 hypothetical species, reasonable confidence for the splitting of 63 putative species and doubtful confidence of cladogenesis for ten species (Supplementary Table S1, Supplementary Fig. S1). For most of the doubtful scenarios, we suspect that species diversity may be higher, but in a few particular cases we suspect over-splitting of species. ...
Context 30
... present preliminary hypotheses about Plumularioidea species-level diversity, to be tested with further mor- phologic and genetic studies (cf. degrees of confidence for each putative species delimitation in Supplementary Table S1 and Supplementary Fig. S1). ...
Context 31
... of morphospecies. The species delimitation analyses did not differentiate in 16 instances between different morphotypes thought to represent distinct species (Supplementary Table S1, Supplementary Fig. S1). In these cases, there is either a need to synonymize taxa, based on the ineffectiveness of the established diagnostic morphological characters to characterize these taxa, low inter-specific sequence divergence, and/or incomplete lineage sorting (or hybridization). ...
Context 32
... number of cryptic species revealed by the genetic data was high, especially for nom- inal species with larger sample sizes and wider geographic ranges (e.g. Antennella secundaria and Plumularia seta- cea) (Supplementary Table S1; Supplementary Figs S1 and S2). The species delimitation analyses proposed species subdivisions (i.e., cryptic diversity) for 13 nominal species of Aglaopheniidae, two of Kirchenpaueriidae s.s., six of Halopterididae and 10 of Plumulariidae (Supplementary Table S1; Supplementary Figs S1 and S2) diversity is much more probable whenever the putative species of the same nominal species are not sister line- ages, which was verified in the following taxa: Aglaophenia acacia, "A. ...
Context 33
... secundaria and Plumularia seta- cea) (Supplementary Table S1; Supplementary Figs S1 and S2). The species delimitation analyses proposed species subdivisions (i.e., cryptic diversity) for 13 nominal species of Aglaopheniidae, two of Kirchenpaueriidae s.s., six of Halopterididae and 10 of Plumulariidae (Supplementary Table S1; Supplementary Figs S1 and S2) diversity is much more probable whenever the putative species of the same nominal species are not sister line- ages, which was verified in the following taxa: Aglaophenia acacia, "A. pluma complex", Gymnangium speciosum, "G. ...
Context 34
... complex", Gymnangium speciosum, "G. allmani and G. sibogae complex" (Aglaopheniidae), Antennella secundaria, A. similis, Halopteris diaphana, H. alternata (Halopterididae), Plumularia strictocarpa, P. setacea, P. floridana, N. antennina (Plumulariidae) (Supplementary Fig. S1). When putative species are sister lineages (e.g., Monostaechas quadridens) they could simply be indicative of intraspecific phylogeographic structuring, or incipient speciation. ...
Context 35
... incipient speciation. Indeed, high levels of population structuring and isolation by distance were revealed with microsatellite data, in two supposedly widely dispersed Indo-Pacific species of Aglaopheniidae 24,61,62 . These cases suggest that most of the cryptic diversity proposed by our species delimitation analyses (Supplementary Table S1 and Fig. S1) is highly probable, and in some cases, we suspect it could be even higher (cf. degrees of confidence for cladogenesis). Cryptic diversity is frequently suggested for lineages of a nominal species obviously separated by a physical barrier (e.g., American Continent) or long distances (e.g, both sides of the Atlantic). But cryptic ...
Context 36
... the taxonomic level of species, we verified some cases of probable conspecific morphotypes, suggesting either synonymies or simply inoperability of morphological diagnostic characters ( Supplementary Fig. S1 and Text S1). Below we list these cases and taxonomic amendments that may be adopted for the following associations of morphospecies, listing the species name with priority first: • Taxella eximia and T. gracilicaulis, probably synonymous; ...
Context 37
... contrast, the numerous cases of probable cryptic diversity highlighted ( Supplementary Figs S1 and S2; Supplementary Text S2) within Aglaopheniidae, Kirchenpaueriidae, Plumulariidae and Halopterididae (Table 1) deserve further haplotype sampling, morphological studies and sequencing of nuclear markers. It is probable that around 34-41% of the richness of the Plumularioidea is cryptic (Table 1), awaiting formal description or resur- rection of nominal species currently unaccepted. ...
Citations
... In regard to the molecular work, we used the most common method of barcoding [4][5][6][7][8]. However, we agree that it would increase the accuracy and robustness of species identification if multiple markers, including mitochondrial COI gene, 16S rRNA, and nuclear ribosomal internal transcribed spacer (ITS) regions can be used together [8][9][10][11][12][13][14][15][16][17]. ...
We appreciate the comments made by Hendawitharana et al [...]
... 96 studies detected several distinct complexes of CS, up to a maximum of 33, often in barcoding studies or phylogenetic studies [e.g. Carr et al. (2011) detected 33 CS in Polychaeta; Moura et al. (2018) detected at least 29 CS in Hydrozoa]. These papers represented 368 CS complexes out of 977. ...
... The larger distribution ranges in nominal species with CS ( Fig. 2) apparently supports the suggestion of Knowlton (1993) that molecular studies usually reveal that 'cosmopolitan' species are species complexes. However, CS complexes often include sympatric biological species each of which have large distribution ranges (Nygren, 2014;Egea et al., 2016;Brasier et al., 2017;Castelin et al., 2017;Fiser et al., 2018;Moura et al., 2018). We therefore cannot rule out that species with large distribution ranges may be more likely to form CS, which could result from multiple potential mechanisms. ...
Genetic data show that many nominal species are composed of more than one biological species, and thus contain cryptic species in the broad sense (including overlooked species). When ignored, cryptic species generate confusion which, beyond biodiversity or vulnerability underestimation, blurs our understanding of ecological and evolutionary processes and may impact the soundness of decisions in conservation or medicine. However, very few hypotheses have been tested about factors that predispose a taxon to contain cryptic or overlooked species. To fill this gap, we surveyed the literature on free‐living marine metazoans and built two data sets, one of 187,603 nominal species and another of 83 classes or phyla, to test several hypotheses, correcting for sequence data availability, taxon size and phylogenetic relatedness. We found a strong effect of scientific history: the probability of a taxon containing cryptic species was highest for the earliest described species and varied among time periods potentially consistently with an influence of prevailing scientific theories. The probability of cryptic species being present was also increased for species with large distribution ranges. They were more frequent in the north polar and south polar zones, contradicting previous predictions of more cryptic species in the tropics, and supporting the hypothesis that many cryptic species diverged recently. The number of cryptic species varied among classes, with an excess in hydrozoans and polychaetes, and a deficit in actinopterygians, for example, but precise class ranking was relatively sensitive to the statistical model used. For all models, biological traits, rather than phylum, appeared responsible for the variation among classes: there were fewer cryptic species than expected in classes with hard skeletons (perhaps because they provide good characters for taxonomy) and image‐forming vision (in which selection against heterospecific mating may enhance morphological divergence), and more in classes with internal fertilisation. We estimate that among marine free‐living metazoans, several thousand additional cryptic species complexes could be identified as more sequence data become available. The factors identified as important for marine animal cryptic species are likely important for other biomes and taxa and should aid many areas in biology that rely on accurate species identification.
... applied for identification and differentiation of cnidarian species (Bucklin et al., 2021;Holst et al., 2019;Holst & Laakmann, 2014;Moura et al., 2018). However, standard fragments such as COI barcodes are not fully informative in all groups on species level Schuchert, 2020). ...
Morphological identification of cnidarian species can be difficult throughout all life stages due to the lack of distinct morphological characters. Moreover, in some cnidarian taxa genetic markers are not fully informative, and in these cases combinations of different markers or additional morphological verifications may be required. Proteomic fingerprinting based on MALDI-TOF mass spectra was previously shown to provide reliable species identification in different metazoans including some cnidarian taxa. For the first time, we tested the method across four cnidarian classes (Staurozoa, Scyphozoa, Anthozoa, Hydrozoa) and included different scyphozoan life-history stages (polyp, ephyra, medusa) in our dataset. Our results revealed reliable species identification based on MALDI-TOF mass spectra across all taxa with species-specific clusters for all 23 analysed species. In addition, proteomic fingerprinting was successful for distinguishing developmental stages, still by retaining a species specific signal. Furthermore, we identified the impact of different salinities in different regions (North Sea and Baltic Sea) on proteomic fingerprints to be negligible. In conclusion, the effects of environmental factors and developmental stages on proteomic fingerprints seem to be low in cnidarians. This would allow using reference libraries built up entirely of adult or cultured cnidarian specimens for the identification of their juvenile stages or specimens from different geographic regions in future biodiversity assessment studies.
... Moreover, fixation of the gelatinous medusae and the soft-bodied polyps can lead to shrinkage and deformation of fragile specimens leading to distortion of morphological diagnostic features (Häussermann, 2004;Schuchert, 2012;Holst and Laakmann, 2014;Holst et al., 2019). Molecular genetic techniques have been widely tested and applied for identification and differentiation of cnidarian species (Holst and Laakmann, 2014;Moura et al., 2018;Holst et al., 2019;Bucklin et al., 2021). However, not in all groups, standard fragments such as the COI barcode regions are fully informative on species level (Brugler et al., 2018;Schuchert, 2020). ...
Morphological identification of cnidarian species can be difficult throughout all life stages due to the lack of distinct morphological characters. Moreover, in some cnidarian taxa genetic markers are not fully informative, and in these cases combinations of different markers or additional morphological verifications may be required. Proteomic fingerprinting based on MALDI-TOF mass spectra was previously shown to provide reliable species identification in different metazoans including some cnidarian taxa. For the first time, we tested the method across four cnidarian classes (Staurozoa, Scyphozoa, Anthozoa, Hydrozoa) and included different scyphozoan life-history stages (polyp, ephyra, medusa) into our dataset. Our results revealed reliable species identification based on MALDI-TOF mass spectra across all taxa with species-specific clusters for all 23 analyzed species. In addition, proteomic fingerprinting was successful for distinguishing developmental stages, still by retaining a species specific signal. Furthermore, we identified the impact of different salinities in different regions (North Sea and Baltic Sea) on proteomic fingerprints to be negligible. In conclusion, the effects of environmental factors and developmental stages on proteomic fingerprints seem to be low in cnidarians. This would allow using reference libraries built up entirely of adult or cultured cnidarian specimens for the identification of their juvenile stages or specimens from different geographic regions in future biodiversity assessment studies.
... DNA barcoding is a fast and accurate method for identifying and characterising species, especially cryptic or unknown, and for assessing biodiversity (Moura et al. 2018). The ideal barcode is a standardised universal short DNA sequence (400-800 bp) that remains stable through many generations within a species, but at the same time, is variable enough to allow discrimination between closely related species (Kress and Erickson 2012a;Hollingsworth et al. 2016). ...
... The COX-1 region has been widely and successfully used for most animal taxa, except a few exceptions, e.g., Cnidaria, for which the mitochondrial rRNA gene for the small ribosomal subunit (16S) was established as a more suitable marker (Herbert et al. 2003;Moura et al. 2018). Further details and protocols on animal DNA barcoding can be found in Kress and Erickson (2012b). ...
... DNA barcoding is a fast and accurate method for identifying and characterising species, especially cryptic or unknown, and for assessing biodiversity (Moura et al. 2018). The ideal barcode is a standardised universal short DNA sequence (400-800 bp) that remains stable through many generations within a species, but at the same time, is variable enough to allow discrimination between closely related species (Kress and Erickson 2012a;Hollingsworth et al. 2016). ...
... The COX-1 region has been widely and successfully used for most animal taxa, except a few exceptions, e.g., Cnidaria, for which the mitochondrial rRNA gene for the small ribosomal subunit (16S) was established as a more suitable marker (Herbert et al. 2003;Moura et al. 2018). Further details and protocols on animal DNA barcoding can be found in Kress and Erickson (2012b). ...
... Cryptic speciation is common in hydrozoans, particularly in presumed widespread species (e.g. Schuchert 2014; Cunha et al. 2017;Postaire et al. 2017a, b;Boissin et al. 2018;Moura et al. 2018;Miglietta et al. 2019;Vaga et al. 2020). However, defining whether these cryptic lineages deserve the species status is not an easy task, and it may not be possible to find morphological diagnostic characters for recognising each lineage, or determining whether there is a deficit of intermediates (see Schuchert 2014;Mallet 1995). ...
Connectivity among populations of widespread marine species is expected to be correlated with their dispersal potential but the evolution of reproductive barriers may account for variations in spatial genetic patterns. Marine benthic hydroid species are traditionally considered widespread, with long-distance rafting presumably increasing their dispersal potential. In this study, we investigated the relationship between genetic, morphological and environmental variability within three benthic marine hydroid species to evaluate current patterns of genetic variation and assess the existence of cryptic speciation. Although a long-lived planktonic stage is absent in all the lineages sampled and they have an overlapping geographical ranges, we observed contrasting patterns of genetic and phenotypic divergence: Orthopyxis sargassicola showed little genetic variation, while O. caliculata and O. crenata each contained high genetic differentiation, primarily suggesting limited dispersal potential. Significant covariation was observed between phenotypic and environmental data in all lineages, but different environmental variables were responsible for explaining morphological variation in each case. Genetic and morphological patterns within O. caliculata and O. crenata are suggestive of cryptic speciation, while phenotypic variation in O. sargassicola may be plastic. Thus, morphological and genetic patterns may potentially vary among related marine lineages with shared life history traits and habitat.
... The species is widespread in shallow waters of the warm western Atlantic Ocean (Oliveira et al. 2016;Calder 2019), although it was long included in the synonymy of the predominantly European H. diaphana (Heller, 1868). Schuchert (1997) distinguished the two on the basis of morphological characters, and their separation as distinct species has been confirmed by DNA barcoding (Galea et al. 2018;Moura et al. 2018). Differences distinguishing H. alternata from related species of the genus Halopteris Allman, 1877) have been reviewed by Schuchert (1997) and Calder et al. (2019). ...
... Halopteris alternata has been reported from the region by Fraser (1938a, as Plumularia alternata) from Mexico (Revillagegedo Islands; east of islands off Navidad Head; Isabel Island), Ecuador (Galápagos Islands; Santa Elena Bay), Colombia (Port Utria) and Panama (Jicarita Island; Pacora Island); by Fraser (1938c, as P. alternata) from Panama (Secas Islands) and Mexico (Isabel Island); by Moura et al. (2018) from Panama (Coiba); and by Calder et al. (2019 from mainland Ecuador (Salinas) and the Galápagos Islands. Elsewhere in the Pacific it occurs in Hawaii (Cooke 1977, as H. diaphana), including the Northwestern Hawaiian Islands (Calder and Faucci 2021). ...
... Its occurrence on Cocos Island thus coincides with the known distribution of the species across the Tropical Eastern Pacific Realm. Elsewhere, M. philippina is taken to be essentially circumglobal in shallow tropical to warm-temperate waters (Moura et al. 2018;Calder and Faucci 2021). As with Halopteris alternata (Nutting, 1900), hydroids of the species from the western Atlantic and eastern Pacific have been shown to share the same 16S haplotypes (Moura et al. 2019). ...
The hydroids of Cocos Island (Isla del Coco), Costa Rica, have received scant attention and are poorly known. Only 11 species have been reported from there previously, with five of them being stylasterids. Hydroids examined here were collected during 2019 in a search for invasive species, as part of a fouling survey. Fourteen species – three anthoathecates and 11 leptothecates – were identified in the collection. All represent new records for Cocos Island, elevating its number of reported species to 25. The most abundant species in the collection were Clytia obliqua (Clarke, 1907) and Sertularella affinicostata Calder and Faucci, 2021, found in 11 of 42 samples (26%), and Tridentata borneensis Billard, 1925a, present in nine (21%) of them. Nematocysts of Corydendrium flabellatum Fraser, 1938a and Eudendrium cf. certicaule Fraser, 1938a are newly identified, measured and illustrated. Three species (Clytia brevithecata (Thornely, 1900), Halopteris alternata (Nutting, 1900) and Macrorhynchia philippina Kirchenpauer, 1872), are introduced, with the rest assigned to a native or cryptogenic status.
... Evidence for recognition of Monotheca as distinct from Plumularia Lamarck, 1816 has been made elsewhere on the basis of both morphology (Calder 1997) and genetics (Moura et al. 2018). Species currently assigned to the genus are small and often epiphytic, although M. obliqua, M. flexuosa, M. margaretta, and M. bergstadi Gil & Ramil, 2021 are or appear to be substrate generalists (Watson 2011a;Gravili et al. 2015;Calder 2019;Gil & Ramil, 2021). ...
... The type species of the genus, by subsequent designation by Stechow (1923c: 215), is Diplocheilus mirabilis Allman, 1883. Molecular phylogenetic studies (Maronna et al. 2016;Moura et al. 2018) confirm the close phylogenetic relationship of Pycnotheca to kirchenpaueriid genera including Kirchenpaueria Jickeli, 1883and Oswaldella Stechow, 1919a. Watson (1990 provided a review of characters useful in distinguishing the three currently recognized species of Pycnotheca. ...
... This is reflected in the extensive distribution records and lengthy synonymy list of the species provided by Ansín Agís et al. (2001). It nevertheless appears certain now that cryptic species exist in hydroids assigned to A. secundaria, with multiple lineages having been distinguished through barcoding sequences (Moura et al. 2018(Moura et al. , 2019. Indeed, Cornelius (1995b) had suspected, based on observed morphological differences, that more than one species was represented under the name. ...
Forty-two species of hydroids, excluding stylasterids, are reported in the present collection from the Northwestern
Hawaiian Islands. Of these, four are anthoathecates and 38 are leptothecates. Among the latter, Sertularella affinicostata
and Monotheca gibbosa are described as new species. The binomen Halopteris longibrachia is proposed as a new
replacement name for Plumularia polymorpha var. sibogae Billard, 1913, an invalid junior primary homonym of P.
sibogae Billard, 1911. Based largely on evidence from earlier molecular phylogenies, the genus Disertasia Neppi, 1917
is resurrected to accommodate species including Dynamena crisioides Lamouroux, 1824, Sertularia disticha Bosc, 1802,
and Sia. moluccana Pictet, 1893. Sertularella robusta Coughtrey, 1876 is an invalid junior primary homonym of Sla. gayi
var. robusta Allman, 1874a, and has been replaced here by the binomen Sla. quasiplana Trebilcock, 1928, originally
described as Sla. robusta var. quasiplana Trebilcock, 1928. Clytia hummelincki (Leloup, 1935) is referred to the synonymy
of its senior subjective synonym, C. brevithecata (Thornely, 1900). Following Reversal of Precedence provisions in
the International Code of Zoological Nomenclature to preserve prevailing usage of binomena, the familiar names Sia.
disticha Bosc, 1802 (also known as Dynamena disticha) and Lytocarpia phyteuma (Stechow, 1919b) are designated
nomena protecta and assigned precedence over their virtually unknown senior synonyms Hydra quinternana Bosc, 1797
and Aglaophenia clavicula Whitelegge, 1899, respectively, names now reduced to the status of nomena oblita. Twenty
species are reported for the first time from Hawaii [Eudendrium merulum Watson, 1985, Phialellidae (undetermined),
Hebella sp., Hebellopsis scandens (Bale, 1888), H. sibogae Billard, 1942, Clytia brevithecata, C. linearis (Thornely,
1900), C. cf. noliformis (McCrady, 1859), Halecium sp., Sla. affinicostata, Sla. angulosa Bale, 1894, Pasya heterodonta
(Jarvis, 1922), Tridentata orthogonalis (Gibbons & Ryland, 1989), Pycnotheca producta (Bale, 1881), Monotheca
gibbosa, H. longibrachia, A. postdentata Billard, 1913, A. suensonii Jäderholm, 1896, A. whiteleggei Bale, 1888, and
L. flexuosa (Lamouroux, 1816)]. Sertularia orthogonalis, reported for only the third time worldwide, is assigned to
the genus Tridentata Stechow, 1920. Hydroids of the NOWRAMP 2002 collection consisted largely of presumptive
widespread species, with over 75% of them having been reported elsewhere in the tropical Indo-west Pacific region.
... Given the lack of genetic material, not only of C. fertilis, but also of many Cladocarpus species and members of Cladocarpus-like genera, and the unpredictable relationships between the few species for which genetic data are already available (Moura et al. 2018), it is impossible for the time being to ascertain the validity of the genus Carpocladus, as well as its phylogenetic position within the family Aglaopheniidae. ...
Two thecate hydroids, Carpocladus fertilis Vervoort & Watson, 2003 (family Aglaopheniidae Marktanner-Turneretscher, 1890) and Gonaxia constricta (Totton, 1930) (family Gonaxiidae Maggioni, in Galea & Maggioni, 2021), are recorded for the first time from off New Caledonia, thus outside their original area of distribution in New Zealand waters. Specimens of both sexes of C. fertilis occur in the present collection, allowing the first description of its so far unknown female gonothecae. The trophosome of G. constricta, the only known to date, is thoroughly redescribed, pending the discovery of its gonothecae.
