Figures 50-59 - uploaded by John D. Taylor
Content may be subject to copyright.
Ctena orbiculata. 50. Venus orbiculata, copy of original figure from Montagu (1808). 51-55. Neotype, Venus orbiculata, Long Key, FMNH 339457, L¼13.6 mm. 51-52. Exterior of right and left valves. 53. Dorsal view of conjoined valves. 54-55. Interior of left and right valves. 56-59. Ctena orbiculata, SEM details of coated specimen from same sample and location as neotype, NHMUK 20130563. 56-57. Hinge teeth of left and right valves. Scale bar ¼ 2 mm. 58. Microsculpture. Scale bar ¼ 10 mm. 59. Protoconch. Scale bar ¼ 50 mm.
Source publication
A new genus, Clathrolucina Taylor and Glover, is proposed for the widely distributed western Adantic species Lucina costata d'Orbigny, 1846, which has previously been placed in Codakia, Ctena, and Parvilucina. Molecular evidence indicates a closer relationship to Radiolucina and Lucinisca. A new species, Ferrocina garciai Taylor and Glover, is desc...
Citations
... No litoral norte do Estado de São Paulo ocorrem espécies de dois gêneros, entre eles Clathrolucina e Parvilucina (Lucininae), que apresentam conchas muito semelhantes. Essas espécies eram, anteriormente, denominadas Codakia costata e Codakia pectinella (Codakininae), tendo sido recentemente alocadas na subfamília Lucininae, com base em filogenia molecular (Taylor et al., 2013). Portanto, a análise ultraestrutural do espermatozoide, realizada pela primeira vez nessas espécies, tem por objetivos adicionar informações relevantes para elucidar as relações entre as subfamílias e contribuir para esclarecer se os representantes analisados são de fato duas espécies de gêneros distintos (P. ...
New molecular phylogenies of the chemosymbiotic bivalve family Lucinidae, using 18S rRNA, 28S rRNA and cytochrome b genes, include species from genera not previously analysed. Notable additions from Myrteinae are sequences from Rostrilucina, Solelucina and Taylorina species, species of Ustalucina, Gonimyrtea from Leucosphaerinae and additional species of Ctena, Codakia, Lucinoma and Divalucina from Codakiinae. New sequences of Lucininae include the type species of Parvilucina (P. tenuisculpta), Liralucina, Falsolucinoma, Easmithia, Jallenia, Radiolucina and Cardiolucina as well as samples of Loripes orbiculatus from multiple localities. Five major clades, defined as subfamilies, are recognized: Pegophyseminae, Myrteinae, Leucosphaerinae, Codakiinae and Lucininae. Two branches, Fimbriinae and Monitilorinae, are represented by single species. Pegophyseminae are an extremely long-branched group with a sister-group relationship to Leucosphaerinae, while Codakiinae are a sister clade to the Lucininae. In various gene trees, the position of Myrteinae is unstable in relation to Pegophyseminae + Leucosphaerinae, Monitilorinae and Fimbriinae. The Myrteinae are not well resolved, with an ambiguous correlation of molecular and morphological characters. Codakiinae now include Divalucina cumingi, shown to be related to Lucinoma rather than Divaricella and Divalinga of the Lucininae. Leucosphaerinae are a well-supported clade but morphologically disparate, with the positions of Gonimyrtea and Callucina unresolved. Several molecularly distinct subclades are recognized within the Lucininae, especially the Lucinisca, Loripes and Parvilucina groups. Parvilucina species are paraphyletic with P. tenuisculpta, the type species, distinct from the western Atlantic species. Codakia, Ctena and Pegophysema have pan-tropical distributions with former connections disrupted by vicariant events of the closure of the eastern Tethyan and Central American Seaways. Species of Radiolucina, Pleurolucina and Lucinisca are present on either side of the Isthmus of Panama. A new classification of the 96 living lucinid genera is presented, providing a framework for future studies of systematics, ecology, biogeography and bacterial symbioses.
In Martinique, some coastal species bivalves are harvested in mangrove swamps and beaches for consumption. Due to their habitat distribution and their life habits, these species are highly bio-accumulators of pollutants. Thus, these fisheries considered a priori, as localized by some authors, provide food resources potentially contaminated by pollutants. However, there are few data on the importance and characteristics of these fisheries; the quantitative assessment of the stock and the state of health of the bivalves being unknown. In addition, since 2011, floating clumps of Sargassum spp are more frequent and therefore lead to increased mortality in coastal biocenoses.These Sargassum algae are known for their ability to accumulate a large amount of metals in their tissues. The released of these substances and in particular arsenic by desorption or by decomposing algal biomass constitute a risk of contamination for coastal biocenoses but also for consumers of bivalves. In this thesis, the importance and characteristics of fisheries as well as of the main species caught were described. The impact of stranding on a bivalve population has been outlined and the state of contamination of the bivalves has highlighted the presence of significant contamination by some metals but especially by arsenic. The exposure of bivalve consumers to these metals has been estimated. These results reveal consumer exposure as the daily intake ranged from1.6 mg.day-1 to 6 mg. day-1 for a meal of 240 g of bivalves. As arsenic has highly toxic chemical species, the proportions of which in the flesh of bivalves could increase in the context of sargassum strandings, the consumption of these bivalves must be limited and away from periods of sargassum strandings. In order to preserve the health of consumers, toxicological reference doses for all the species of arsenic present in the flesh of these bivalves are proposed and discussed.
Keywords: traditional fishing practices, consumption of bivalves, bivalves biometrics, arsenic exposure assessment, arsenic speciation in bivalves, sargassum stranding.
A complete list of new molluscan taxa introduced by Col. George Montagu (1753–1815) is presented. The available type material of these taxa are itemised and illustrated. The majority are present in the Royal Albert Memorial Museum & Art Gallery, Exeter with a smaller number in the Natural History Museum, London. The historic background of both collections is reviewed with special reference to the many non-British species spuriously introduced into Testacea Britannica and its Supplement.
Intensive sampling of molluscs from the intertidal to depths of 800 m around the islands of Guadeloupe in the Lesser Antilles (KARUBENTHOS 2012, 2015) recovered 25 species of Lucinidae. All the Guadeloupe species are described and illustrated including details of larval shells and the taxonomy revised within the context of the wider western Atlantic fauna and recent classifications. Concurrent molecular analysis has helped separate frequently confounded species. ‘Myrtea’ pristiphora is placed in the Leucosphaerine genus Myrtina previously known from the Indo-West Pacific. A second western Atlantic species of Callucina, C. pauperatus previously known from the Pliocene of Jamaica is recognised from the southern Caribbean and off Brazil. The deeper water species ‘Myrteopis’ lens is placed in Afrolucina previously known from the eastern Atlantic. Lucinids commonly identified as Ctena orbiculata are shown to belong to two distinct species, C. orbiculata in the Gulf of Mexico and Florida and C. imbricatula in the Caribbean. Epicodakia is recognised for the first time in the western Atlantic with E. pectinata widely distributed across the region and E. filiata recorded from deeper water. Three species of Lucina are recognised, Lucina pensylvanica in the Gulf of Mexico and Florida and the similar Lucina roquesana from the Caribbean and Bahamas while the smaller L. aurantia has a wide distribution from central America to the Bahamas. A new species of Parvilucina, P. latens is described; this is similar to P. pectinella but has an internal ligament. The long problematic species ‘Codakia’ cubana is assigned to Ferrocina. A new genus, Guyanella is introduced for Parvilucina clenchi the smallest known lucinid. A critical reassessment of the lucinid fauna of the western Atlantic Ocean identifies 46 species for the region with 33 of these living at depths less than 200 m. Deeper-water habitats have been much less investigated except at sites of hydrocarbon seeps. Some species are widespread throught the whole region but others have more restricted ranges. Notable are species pairs, for example of Ctena, Lucina, Lucinisca and Parvilucina that are either largely Caribbean or Gulf of Mexico/Floridian in distribution. Although extralimital, two problematic species from the mid-south Atlantic island of St Helena are refigured and placed in Cavilinga.
A new molecular phylogeny of the Lucinidae using 18S and 28S rRNA and cytochrome b genes includes many species from the tropical Western Atlantic as well as additional taxa from the Indo-West Pacific. This study provides a phylogenetic framework for a new taxonomy of tropical Western Atlantic lucinids. The analysis confirmed five major clades—Pegophyseminae, Leucosphaerinae, Myrteinae, Codakiinae and Lucininae, with Monitilorinae and Fimbriinae represented by single species. The Leucosphaerinae are expanded and include Callucina winckworthi and the W. Atlantic Myrtina pristiphora that groups with several Indo-West Pacific Myrtina species. Within the Codakiinae two abundant species of Ctena from the Western Atlantic with similar shells are discriminated as C. orbiculata and C. imbricatula, while in the Indo-West Pacific Ctena bella is a probable species complex. The Lucininae is the most species rich and disparate subfamily with several subclades apparent. Three species of Lucina are recognized in the W. Atlantic L. aurantia, L. pensylvanica and L. roquesana. Pleurolucina groups near to Cavilinga and Lucina, while Lucinisca muricata is more closely related to the E. Pacific L. fenestrata than to the Atlantic L. nassula. A new species of Parvilucina is identified from molecular analyses having been confounded with Parvilucina pectinata but differs in ligament structure. Also, the former Parvilucina clenchi is more distant and assigned to Guyanella.
A new shallow water species of the lucinid bivalve Pleurolucina is described from Curaçao in the southern Caribbean Sea and compared with known species of the genus from the western Atlantic and eastern Pacific Oceans. Although confused with the Floridian species P. leucocyma, it is most similar to the eastern Pacific P. undata. As in all studied lucinids, the new species possesses symbiotic bacteria housed in the ctenidia. The shell microstructure is unusual with repeated and intercalated conchiolin layers that have sublayers of ‘tulip-shaped’ calcareous spherules. Predatory drillings by naticid gastropods frequently terminate at the conchiolin layers.
A survey of the lucinid bivalves of Singapore recorded 18 species, 12 of these located during the Singapore Strait Biodiversity Workshop, two others previously collected from the Straits of Johor and a further four species identified from museum specimens. These are illustrated and briefly described. In 2013 survey, lucinids were uncommon at most locations but a seagrass bed at the southern end of the artificially constructed beach joining Seringat and Lazarus islands, yielded 9 species of lucinids and numerous other infaunal bivalves. By far the most abundant species was the small Pillucina profusa, with fewer numbers of Euanodontia ovum, Cardiolucina macassari, Cavatidens bullula, Leucosphaera philippinensis and Liralucina lyngei. The associated infaunal bivalves included 36 species from 10 families; the most diverse were Tellinidae with 14 species and these are illustrated to assist local identification. Three lucinids, Austriella corrugata, Indoaustriella dalli, and Pegophysema philippiana occurred amongst mangroves in the Strait of Johor. Species for which only museum records are available, such as Codakia paytenorum and Lepidolucina venusta, may be locally extinct. Five Singapore lucinid species were included in a new molecular analysis (18S, 28S and cytochrome b genes) to establish their phylogenetic relationships and anatomical details including, in particular, ctenidial structure and morphology of bacterial symbionts for Eunanodontia ovum and Pillucina profusa.
