FIGS 21 - uploaded by Rüdiger Bieler
Content may be subject to copyright.
, 22. Anatomy of Dendropoma lituella (Mörch, 1861), based on a partial dried specimen that has been rehydrated. FMNH 1689, San Diego, U.S.A. Scale bars = 1 mm. FIG. 21: Right view of head; FIG. 22: Mantle cavity.
Source publication
Identifying natural groups within the caenogastropod family Vermetidae has proven challenging. The sessile lifestyle of vermetids, with associated xenomorphically distorted, overgrown and corroded shells, has resulted in a long and confused taxonomic history based primarily on adult shell characters. In this study, we use morphological, anatomical...
Citations
... Studies of vermetid predation are sparse, but main predators are known to include fish (such as pufferfish, triggerfish, and parrotfish), sea stars, crab, octopus, and neogastropods (e.g., Menge et al., 1986;Osman, 1987;Calvo & Templado, 2005;Ramírez et al., 2013;Shima, Phillips & Osenberg, 2016;Brown et al., 2014;Shlesinger, Akkaynak & Loya, 2021). In intertidal and reef environments with strong predation pressure by grazing and scraping fish, the defense strategy by members of some genera (Dendropoma, Novastoa) includes building strong low-lying shells, reducing the profile further by actively entrenching into the substratum by radula action, and closing the aperture with a large operculum that is held shut by the animal's strong columellar muscle (Golding et al., 2014;Schiaparelli et al., 2017;Bieler, 1983Bieler, -2023. Other vermetid groups (Vermetus, expeditions spanning more than 40 years, see below. ...
... Anatomical and Morphological Studies: We used the protocols outlined in Golding et al. (2014) and the treatment of Thylacodes species mirrors that for the species described in Bieler et al. (2017a). Author/date references, acceptance of valid species, and higher taxonomic units follow the treatment in MolluscaBase eds (2023), except where specifically noted. ...
... Molecular Systematics: Our molecular sampling focused on 11 non-operculate vermetid specimens from the western Atlantic. Molecular procedures largely followed those outlined in Golding et al. (2014), with modifications highlighted below. In short, specimens for DNA extraction were preserved in 70-95% ethanol or RNAlater. ...
Vermetid worm-snails are sessile and irregularly coiled marine mollusks common in warmer nearshore and coral reef environments that are subject to high predation pressures by fish. Often cryptic, some have evolved sturdy shells or long columellar muscles allowing quick withdrawal into better protected parts of the shell tube, and most have variously developed opercula that protect and seal the shell aperture trapdoor-like. Members of Thylacodes (previously: Serpulorbis ) lack such opercular protection. Its species often show polychromatic head-foot coloration, and some have aposematic coloration likely directed at fish predators. A new polychromatic species, Thylacodes bermudensis n. sp., is described from Bermuda and compared morphologically and by DNA barcode markers to the likewise polychromatic western Atlantic species T. decussatus (Gmelin, 1791). Operculum loss, previously assumed to be an autapomorphy of Thylacodes , is shown to have occurred convergently in a second clade of the family, for which a new genus Cayo n. gen. and four new western Atlantic species are introduced: C. margarita n. sp. (type species; with type locality in the Florida Keys), C. galbinus n. sp., C. refulgens n. sp., and C. brunneimaculatus n. sp. (the last three with type locality in the Belizean reef) (all new taxa authored by Bieler, Collins, Golding & Rawlings). Cayo n. gen. differs from Thylacodes in morphology (e.g., a protoconch that is wider than tall), behavior (including deep shell entrenchment into the substratum), reproductive biology (fewer egg capsules and eggs per female; an obliquely attached egg capsule stalk), and in some species, a luminous, “neon-like”, head-foot coloration. Comparative investigation of the eusperm and parasperm ultrastructure also revealed differences, with a laterally flattened eusperm acrosome observed in two species of Cayo n. gen. and a spiral keel on the eusperm nucleus in one, the latter feature currently unique within the family. A molecular phylogenetic analysis based on mitochondrial and nuclear rRNA gene sequences (12SrRNA, trnV, 16SrRNA, 28SrRNA) strongly supports the independent evolution of the two non-operculate lineages of vermetids. Thylacodes forms a sister grouping to a clade comprising Petaloconchus , Eualetes , and Cupolaconcha, whereas Cayo n. gen is strongly allied with the small-operculate species Vermetus triquetrus and V. bieleri . COI barcode markers provide support for the species-level status of the new taxa. Aspects of predator avoidance/deterrence are discussed for these non-operculate vermetids, which appear to involve warning coloration, aggressive behavior when approached by fish, and deployment of mucous feeding nets that have been shown, for one vermetid in a prior study, to contain bioactive metabolites avoided by fish. As such, non-operculate vermetids show characteristics similar to nudibranch slugs for which the evolution of warning coloration and chemical defenses has been explored previously.
... In addition, it further protects the terrestrial snail soft body from arid environments and desiccation (Páll-Gergely et al. 2016b). Moreover, operculum structure is another character commonly used for higher-level taxonomic purposes and has proved to carry a phylogenetic signal (Ponder 1998;Kaim and Sztajner 2005;Wilmsmeier and Neubert 2012;Golding et al. 2014;Simone 2020). For instance, in the terbinid marine vertigastropods, the primitive state is a corneous operculum, while a calcareous operculum occurs in more derived members (Checa and Jiménez-Jiménez 1998;Williams and Ozawa 2006;Vermeij and Williams 2007). ...
The snorkel snail genus Rhiostoma Benson, 1860 is comprised of terrestrial cyclophorid snails with wide-ranging species diversity and radiation in Southeast Asia. The typical characters of the genus are a depressed shell, a detached and descending portion of the last whorl with a distinctive peristomal breathing device attached, and a calcareous cup-shaped operculum. Herein, we have revised the systematics of extant species based on shell morphology combined with COI barcoding. From these thirty recognised species, twelve are described as new to science: R. ? amarapuraense sp. nov. , R. anceyi sp. nov. , R. breviocollar sp. nov. , R. ebenozostera sp. nov. , R. cheliopegma sp. nov. , R. furfurosum sp. nov. , R. gnomus , sp. nov. , R. lannaense sp. nov. , R. laoense sp. nov. , R. platymorpha sp. nov. , R. rhothonotaphrosa sp. nov. , and R. tigrina sp. nov. All conchological characters are provided via illustrations of type specimens and living snails, and descriptions of the shells and radulae. Phylogenetic analysis based on partial COI gene sequences strongly supports the designated morphospecies and a monophyletic Rhiostoma , confirming that all pterocyclinid snails with a calcareous, cup-shaped operculum belong to the same clade. A high intra-specific divergence was observed in R. jalorensis and R. housei populations from locations in close proximity, suggesting a lower dispersal and higher level of isolation. The low inter-specific divergence found in R. hainesi , R. samuiense , R. asiphon , and R. rhothonotaphrosa sp. nov. supports their recent diversification and local adaptation, and is congruent with their marked morphological differences. Finally, nine formerly Rhiostoma -placed species were reclassified into either the genus Cyclotus or the genus Opisthoporus .
... For vermetids, the scheme in WORMS has been used herein (2021, https://www.marinespecies.org), which does include the taxonomy proposed by Golding et al. (2014). ...
... Vermetids (Family Vermetidae, Class Gastropoda) include species of sessile, suspension-feeding, irregularly coiled marine snails living in warm temperate and tropical oceans (Golding et al., 2014). They attach to hard substrates, including CCA, dead and living coral (Fig. 5) and have deleterious effects on reef building corals by reducing their skeletal growth and survival (Zvuloni et al., 2008;Shima et al., 2010Shima et al., , 2013. ...
... Dendropoma sp. was identified as the most abundant framework builder after CCA in the raised reef rim both in the windward and leeward sides of Atol das Rocas in Brazil (Gherardi & Bosence, 2001). In the fringing reefs of Abrolhos Archipelago in the eastern Brazilian shelf, 'Dendropoma' irregulare (uncertain generic placement = Vermetus irregularis, Golding et al., 2014) is an important component, together with Porolithon antillarum (as P. pachydermum) of reef edges, which at high tide have an average depth of 2 m and are subaerially exposed at low tide (Tâmega et al., 2014;Spotorno-Oliveira et al., 2015; Table 1). ...
Corals, coralline algae and vermetid gastropods are indirect (marine limiting) relative sea-level (RSL) indicators. The precision in sea-level reconstruction based on fossils of those organisms depends on the probable palaeodepth in which they grew. Constraining such palaeodepth depends, in turn, on the available information about the habitats of their living counterparts. Diverse genera, species and species assemblages of corals, coralline algae and vermetid gastropods have historically been proposed as reliable indicators of narrow, shallow depth ranges. However, the increased information on depth distribution of marine benthos in the last two decades has challenged some early assumptions about depth ranges of taxa considered diagnostic of precise palaeodepths. Here, the authors test the reliability of coral, coralline algal and vermetid assemblages that have been extensively used in RSL reconstructions in the light of data from Ocean Biogeographical Information System (OBIS) and other recently published data. In the Indo-Pacific province, these data support the use of the robust-branching and the shallow, high-energy encrusting coral assemblages with a 0 to 10 m uncertainty. In both cases many component species have unimodal distributions and both median and average water depths are shallower than 10 m. The reliability of these coral assemblages as indicative of shallow water depths is strengthened when corals are encrusted by thick plants of the coralline alga Porolithon gr. onkodes. According to OBIS data, coralline algae of this species group in the Indo-Pacific are restricted to very shallow waters (95% probability of occurrence shallower than 0.2 m and in 99.6% of records shallower than 6 m). However, such a narrow depth range and the overall scarce data on coralline algal species in the OBIS database are questionable due to difficulties of coralline algal species identification with the naked eye. A comprehensive survey of the modern distribution of coralline algae at One Tree Reef (southern Great Barrier Reef) indicates that P. gr. onkodes has a log-normal distribution with median depth of less than 5 m and 95% of occurrence probability of thick crusts (> 0.2 mm) shallower than 8.8 m. Data on modern distribution of vermetids are scarce. In the OBIS database, vermetid species are reported from relatively wide depth ranges. However, relatively high densities (> 10 individuals per m2) on coral and coralline algal surfaces only occur from above mean low tide to some 6 m depth. In the Western Atlantic-Caribbean province Acropora palmata is the most precise RSL marker and no additional components of fossil assemblages improve its palaeodepth information. The confident use of coralgal and vermetid assemblages as RSL indicators relies on the identification of fossil corals and coralline algae at the species or species-group level. The scarcity of available data highlights the need for further studies on distribution of coralline algal species and vermetid in modern coral reefs from a variety of oceans and reef settings.
... Genetic investigations have been conducted on some species of Vermetidae, mostly on Dendropoma Mörch, 1861 from the Mediterranean (e.g. Calvo et al. , 2009Calvo et al. , , 2015Golding et al ., 2014 ;López-Marquez et al ., 2018 ), with a single study dealing with Petaloconchus Lea, 1843 from the Caribbean Sea ( Weinberger et al ., 2010 ). ...
This study aimed to investigate whether the marine snails Petaloconchus varians (d’Orbigny, 1839) and Petaloconchus myrakeenae Absalão & Rios, 1987 from southeastern Brazil are conspecific. Both species were described from Rio de Janeiro, and they diverge mainly in their growth forms (i.e. gregarious for P. varians and solitary for P. myrakeenae). Examination of shell features, operculum, radula and anatomic details revealed no differences between the species. Analysis of partial cytochrome c oxidase subunits I (CO1) sequences showed that all Petaloconchus samples from Rio de Janeiro clustered into a single clade, which included specimens from the Caribbean (Venezuela). In addition, a genetic differentiation test showed that the analysed populations are structured, that the species likely originated in the Caribbean and has undergone significant population expansion. We conclude that P. myrakeenae is a junior synonym of P. varians and provide a morphological redescription of the latter. Furthermore, we argue that different growth forms of P. varians are ecophenotypes, apparently influenced by wave action and water temperature. Tests should be conducted to confirm this hypothesis and to evaluate the impact of other parameters on the plasticity of growth forms, such as food supply and habitat heterogeneity.
... Novastoa sp. can readily be distinguished from the same taxon (named as Dendropoma sp.) previous recorded at the oceanic islands (Rocas Atoll and Fernando de Noronha Archipelago) and along the Northeast Brazilian coast (Maranhão, Alagoas, and Bahia) Tâmega & Bemvenuti, 2012), by the shell and prehatching larval shells extracted from egg masses. The genus Novastoa Finlay, 1926 was recognised by Golding et al. (2014) after revising the genus Dendropoma Mörch, 1861 (s. lat.) both from a molecular and morphological analyses. ...
Despite the increasing focus on biodiversity of mesophotic coral ecosystems (MCEs) on a global scale, some biological groups, such as molluscs, are still poorly investigated. The taxonomic diversity of the molluscan fauna of a scarcely known MCE of the Western Equatorial Atlantic, Northeastern Brazil, was surveyed. Samples were collected along the shallower strata of the upper mesophotic zone (between 33-36 m depth). Twenty-one taxa (nine species of gastropods, ten species of bivalves, and two taxa of chitons) were listed, two of which (Novastoa sp. and Thylaeodus sp.) are potential endemic species. A new northern limit of distribution of Persicula moscatellii was established and seven species had new bathymetric records for living specimens (Barbatia domingensis, Barbatia cancellaria, Lamychaena hians, Leiosolenus bisulcatus, Pinctada imbricata, Hipponix incurvus, and Persicula moscatellii). Hipponix costellatus are the most representative species with 49 individuals, followed by Lima caribaea with six individuals. The present work is the first contribution to the knowledge of the molluscan fauna associated with consolidated substrates from this little-known MCE.
... A and sp. B are sister in all phylogenetic analyses, but infect species of Dendropoma and Thylacodes (distantly related genera within the Vermetidae according to Golding et al. (2014)), respectively. This pattern is also seen between L. learedi and the four species of Hapalotrema, with L. learedi infecting Thylaeodus cf. ...
Blood flukes of the family Spirorchiidae Stunkard, 1921 are significant pathogens of marine turtles, both in the wild and in captivity. Despite causing considerable disease and mortality, little is known about the life cycles of marine species, with just four reports globally. No complete life cycle has been elucidated for any named species of marine spirorchiid, but the group is reported to use vermetid and fissurellid gastropods, and terebelliform polychaetes as intermediate hosts. Here we report molecular evidence that nine related spirorchiid species infect vermetid gastropods as first intermediate hosts from four localities along the coast of Queensland, Australia. ITS2 rDNA and cox1 mtDNA sequence data generated from vermetid infections provides the first definitive identifications for the intermediate hosts for the four species of Hapalotrema Looss, 1899 and Learedius learedi Price, 1934. Additionally, we provide a new locality report for larval stages of Amphiorchis sp., and evidence of three additional unidentified spirorchiid species in Australian waters. Based on the wealth of infections from vermetids during this study, we conclude that the previous preliminary report of a fissurellid limpet as the intermediate host for L. learedi was likely mistaken. The nine species found infecting vermetids during this study form a strongly supported clade exclusive of species of the other two marine spirorchiid genera for which sequence data are available; Carettacola Manter & Larson, 1950 which falls sister to the vermetid-infecting clade + a small clade of freshwater spirorchiids, and Neospirorchis Price, 1934 which is distantly related to the vermetid-infecting clade. We provide further evidence that spirorchiid transmission can occur in closed system aquaria and show that spirorchiid transmission occurs at both an important turtle rookery (Heron Island, southern Great Barrier Reef, Australia) and foraging ground (Moreton Bay, Australia). We discuss the implications of our findings for the epidemiology of the disease, control in captivity, and the evolution of vermetid exploitation by the Spirorchiidae.
... The shell growth and direction of the distal ends may frequently change in response to damage, water currents, and obstacles (Schiaparelli and Cattaneo-Vietti 1999), resulting in their typically irregularly or haphazardly coiled appearance. The inherent high variability of their shell shape and characteristics make taxonomic identification challenging (Bieler and Petit 2011;Golding et al. 2014). ...
... We examined vermetid specimens deposited at the Zoological Reference Collection (ZRC) of the Lee Kong Chian Natural History Museum, National University of Singapore, including material from the Comprehensive Marine Biodiversity Survey of Singapore (see Tan et al. 2016). Morphological characters were compared to figures within Chenu (1843), and descriptions in Keen (1971b), and Hadfield et al. (1972, as Vermetus alii, a widely accepted junior subjective synonym [see Golding et al. 2014;Spotorno-Oliviera et al. 2018]). ...
The Vermetidae is a family of sessile marine gastropods whose members are difficult to identify accurately, but one species, Eualetes tulipa is widely documented as an introduced species globally. In Asia, there is only one known record of this species from India to date. We report the presence of E. tulipa in Singapore based on DNA barcoding. This is the second known record from Asia and the first confirmation of a non-native vermetid for Southeast Asia.
... Vermetids include at least 160 extant species that are mainly found in warm-temperate and tropical shallow waters all around the world (Keen, 1961;Morton, 1965;Safriel, 1966;Laborel, 1987;Hughes, 1993;Gould, 1994;Antonioli et al., 1999;Schiaparelli et al., 2006;Golding et al., 2014). Their remarkable variability of growth forms and the difficulty in finding diagnostic characters (Bieler and Petit, 2011;Golding et al., 2014) have always brought uncertainty in taxonomic determinations, causing great confusion in their systematics and even misidentifications with completely unrelated organisms (Keen, 1961;Gould, 1994). ...
... Vermetids include at least 160 extant species that are mainly found in warm-temperate and tropical shallow waters all around the world (Keen, 1961;Morton, 1965;Safriel, 1966;Laborel, 1987;Hughes, 1993;Gould, 1994;Antonioli et al., 1999;Schiaparelli et al., 2006;Golding et al., 2014). Their remarkable variability of growth forms and the difficulty in finding diagnostic characters (Bieler and Petit, 2011;Golding et al., 2014) have always brought uncertainty in taxonomic determinations, causing great confusion in their systematics and even misidentifications with completely unrelated organisms (Keen, 1961;Gould, 1994). Difficulties have been even greater as regards the fossil record, with many extinct species remaining so far undescribed. ...
... The description of this new species has been complemented with observations on vermetid aggregates from the two other sites. The studied specimens were assigned to a new species of Vermetidae following the most recent systematic literature on the subject (Keen, 1961;Morton, 1965;Gould, 1994;Bieler, 1995;Savazzi, 1996;Bouchet and Rocroi, 2005;Bieler andPetit, 2010, 2011;Golding et al., 2014;Bieler et al., 2015). ...
Exquisitely preserved fossils of a new reef-building vermetid species from shallow-marine lower Miocene (Burdigalian) deposits of the Chilcatay Formation and upper Miocene (Tortonian) sediments of the Pisco Formation of Peru are here reported and described in detail for the first time. These finds are assigned to the living genus Thylacodes and recognized as representatives of a new species, Thylacodes devriesi sp. nov. This new taxon is known by long, almost straight tube-like shells that display peculiar ornamentations in form of striated lamellae and are arranged in an organ-pipe fashion. This discovery represents an important addition to the knowledge of the systematics and distribution of Thylacodes in South America in the geological past. Paleoenvironmental and taphonomic inferences drawn by the fossil remains of this reef-forming species are herein discussed for both the Chilcatay and Pisco formations in the broader framework of the South American fossil record of Vermetidae.
... Therefore, although a relatively limited length of rocky coastline (830m) was surveyed for the purpose of this study, we maintain that the UAVs could be largely used to analyze under a structural point of view this type of extended bioconstructions of intertidal coastal zones, greatly reducing sampling effort. Finally, UAVs represent also a low-cost, long-term and easily applicable monitoring tool that might be of primary importance for the conservation of D. cristatum, a key-species of shallow rocky coasts attributable to the "world-wide worm-snail group" defined by Golding et al. (2014). ...
Vermetid bioconstructions are biogenic formations, built by sessile gastropod molluscs belonging to the family Vermetidae worldwide distributed, occurring in the intertidal and upper subtidal in the rocky shores. In the Mediterranean basin, they occur in complex and tridimensional structures that enhance the local biodiversity, allowing to qualify the structuring species as ecosystem engineers. Due to their ecological relevance and considerable extension along the coasts, we assessed their structural complexity using unmanned aerial vehicle (UAV) technology, as tool of littoral cartography analysis of these bioconstructions, and plaster hemispheres dissolution as a descriptor index of the water movement on them. We adopted an UAV to produce a very high spatial resolution map along 830m of rocky coast where these vermetid gastropods occur. Through an orthophoto with a GSD (Ground Sample Distance) of 1 cm, different complexity values of indentation degree (or roughness profiles) of the reef boundaries were detected, corroborating literature data carried out with traditional measurement techniques (e.g., tape measure). Our results indicate that the most complex zone of reef is the outer edge, facing the open sea, with a decreasing trend toward the inner edge. Concerning the experimental approach conducted using plaster hemispheres placed along the platform, it reveals that water movement is a structuring factor of the vermetid reef complexity along the rocky coast. Overall, the application of UAV technique allows an appropriate approach to analyze different zones of the vermetid reefs with a high-accuracy on a large spatial scale, greatly reducing sampling effort, and generating important implications for future monitoring and conservation programs.
... It is considered a hotspot of biodiversity, with approximately 17,000 species reported in the whole basin (Coll et al., 2010). Part of this rich biodiversity comes from several unique and threatened habitats, such as the seagrass meadows of the endemic Posidonia oceanica, the coralligenous assemblages, the rhodolith beds, and the forests of fucoid algae (Golding et al., 2014). In addition, some bioconstructions improve habitat heterogeneity in the narrow Mediterranean intertidal fringe, and hence increase its biodiversity; such as by the coralline red alga Lithophyllum byssoides and vermetid tubeworm reefs (Ape et al., 2018). ...
Reefs of the tube forming gastropods of the family Vermetidae are key intertidal habitats that prevent wave-induced coastal erosion and enhance species richness. In the Mediterranean Sea, vermetid reefs are built by four mollusc species that have long been considered as one species. Despite their importance as habitat engineers, their level of protection remains poor, and whole community collapses have been recorded recently. Here, we provide an extensive review of the vermetid reefs reported in the Mediterranean from 1970 until 2020, and we analyze their level of protection in the basin. Our results highlight the spatial heterogeneity of the whole complex and reveals a concerning situation: although most of the community collapses have been recorded in the eastern basin, the level of protection in the region remains strikingly low. Effective protection is urgent to preserve these key species and the local high biodiversity associated to it.
