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We describe two new genera of Triassic Aviculopectinoidea: Cristaflabellum n. gen., which is biconvex and has a strongly plicate shell, and Globodiscus n. gen., which is equiconvex and externally smooth or nearly so. Globodiscus contains the new species G. kiliani n. gen. n. sp. and G. vinzenti n. gen. n. sp. In order to make the taxonomic concept of the superfamily Aviculopectinoidea more consistent with that of its sister group Pectinoidea (scallops), we use tribes rather than families or subfamilies for accommodating the new taxa. Cristaflabellum is placed in the tribe Antijanirini (previously family Antijaniridae), whereas Globodiscus is made the type genus of the new tribe Globodiscini. Both tribes are placed within the family Aviculopectinidae, which is revised to include both equiconvex and inequiconvex taxa. We suggest that tribes are a more appropriate taxonomic rank for many of the previously erected species-poor families and subfamilies of Aviculopectinoidea.UUID: http://zoobank.org/d143663a-9016-459f-8e24-660102adcf6a

Dijkstra, Henk H., Beu, Alan G. (2018): Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae). Records of the Australian Museum (Rec. Aust. Mus.) 70 (2): 113-330, DOI: 10.3853/j.2201-4349.70.2018.1670, URL: http://dx.doi.org/10.3853/j.2201-4349.70.2018.1670

Twenty species of Pectinoidea (12 Propeamussiidae, three Cyclochlamydidae, five Pectinidae) are herein listed. Six new species of Pectinoidea (three Propeamussiidae, three Cyclochlamydidae) are from littoral and bathyal depths of the western and southwestern Pacific, sampled by various expeditions and cruises to Papua New Guinea and the South China Sea, viz. Propeamussium regillum n. sp. from the bathyal Bismarck and Solomon Seas, Parvamussium minusculum n. sp. from the lower bathyal South China Sea, Cyclopecten inoculatus n. sp. from the bathyal Bismarck Sea, Cyclochlamys corrugata n. sp., Cyclochlamys barbatula n. sp. and Micropecten reticulatus n. sp. from shallow coastal waters of Papua New Guinea. Fourteen species of Pectinoidea (nine Propeamussiidae, five Pectinidae) are new records for the Bismarck Sea (five), for the Solomon Sea (four), and for the South China Sea (seven).

Twenty-five species of Pectinoidea (24 Propeamussiidae, 1 Cyclochlamydidae) are herein listed from the Mozambique Channel, northwestern and southern Madagascar, and northeastern South Africa. New species: Propeamussium rosadoi, Parvamussium catillus, Parvamussium kilburni, Parvamussium puillandrei, Parvamussium strongae, Cyclopecten cassiculus, Cyclopecten kantori, Cyclochlamys bacachorda. New synonym: Amussium sewelli Knudsen, 1967 = Propeamussium watsoni (E.A. Smith, 1885). New records for the Mozambique Channel and northwestern Madagascar: Propeamussium andamanicum, Propeamussium arabicum, Propeamussium caducum, Propeamussium jeffreysii, Propeamussium sibogai, Propeamussium watsoni, Parvamussium formosum, Parvamussium scitulum, Parvamussium torresi, Parvamussium vesiculatum, Cyclopecten kapalae, Similipecten eous. New records for southern Madagascar: Propeamussium jeffreysii, Propeamussium sibogai, Propeamussium watsoni, Parvamussium formosum, Parvamussium scitulum, Parvamussium thyrideum, Par...

A new species of the bivalve family Cyclochlamydidae is described from the southwestern Atlantic in Argentine waters. Cyclochlamys argentina sp. nov. is the second representative of the genus known to live in the Magellanic area. In addition, this long-lived species is also recorded from lower Miocene rocks in the province of Santa Cruz exposed along the Atlantic coast of the Monte León National Park. The material was collected from the Punta Entrada Member of the Monte León Formation. These small mollusks clearly belong in Cyclochlamys because of shell characters such as the irregularly pitted prodissoconch I and right valve with commarginally elongated rectangular prisms over most of disc. Cyclochlamys argentina sp. nov. shows affinities with taxa such as C. aupouria and C. shepherdi, all of which are known from areas of New Zealand. Fil: Pastorino, Roberto Santiago Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Griffin, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleozoología Invertebrados; Argentina

Mitotic chromosome preparations of the interspecific hybrids Chlamys farreri (Jones & Preston, 1904) × Patinopecten yessoensis (Jay, 1857), C. farreri × Argopecten irradians (Lamarck, 1819) and C. farreri × Mimachlamys nobilis (Reeve, 1852) were used to compare two different scallop genomes in a single slide. Although genomic in situ hybridization (GISH) using genomic DNA from each scallop species as probe painted mitotic chromosomes of the interspecific hybrids, the painting results were not uniform; instead it showed species-specific distribution patterns of fluorescent signals among the chromosomes. The most prominent GISH-bands were mainly located at centromeric or telomeric regions of scallop chromosomes. In order to illustrate the sequence constitution of the GISH-bands, the satellite Cf303 sequences of C. farreri and the vertebrate telomeric (TTAGGG)n sequences were used to map mitotic chromosomes of C. farreri by fluorescence in situ hybridization (FISH). The results indicated that the GISH-banding pattern presented by the chromosomes of C. farreri is mainly due to the distribution of the satellite Cf303 DNA, therefore suggesting that the GISH-banding patterns found in the other three scallops could also be the result of the chromosomal distribution of other species-specific satellite DNAs.

Interspecific crossing was artificially carried out between Chlamys farreri (Jones & Preston, 1904) ♀ and Argopecten irradians irradians (Lamarck, 1819) ♂, two of the dominant cultivated scallop species in China. Genomic in situ hybridization (GISH) was used to examine the chromosome constitution and variation in hybrids at early embryonic stage. The number of chromosomes in 66.38% of the metaphases was 2n = 35 and the karyotype was 2n = 3 m + 5 sm + 16 st + 11 t. After GISH, two parental genomes were clearly distinguished in hybrids, most of which comprised 19 chromosomes derived from their female parent (Chlamys farreri) and 16 chromosomes from their male parent (Argopecten irradians irradians). Some chromosome elimination and fragmentation was also observed in the hybrids.

Twenty-five species of Pectinoidea (24 Propeamussiidae, 1 Cyclochlamydidae) are herein listed from the Mozambique Channel, northwestern and southern Madagascar, and northeastern South Africa. New species: Propeamussium rosadoi, Parvamussium catillus, Parvamussium kilburni, Parvamussium puillandrei, Parvamussium strongae, Cyclopecten cassiculus, Cyclopecten kantori, Cyclochlamys bacachorda. New synonym: Amussium sewelli Knudsen, 1967 = Propeamussium watsoni (E.A. Smith, 1885). New records for the Mozambique Channel and northwestern Madagascar: Propeamussium andamanicum, Propeamussium arabicum, Propeamussium caducum, Propeamussium jeffreysii, Propeamussium sibogai, Propeamussium watsoni, Parvamussium formosum, Parvamussium scitulum, Parvamussium torresi, Parvamussium vesiculatum, Cyclopecten kapalae, Similipecten eous. New records for southern Madagascar: Propeamussium jeffreysii, Propeamussium sibogai, Propeamussium watsoni, Parvamussium formosum, Parvamussium scitulum, Parvamussium thyrideum, Parvamussium vesiculatum, Parvamussium vidalense, Cyclopecten kapalae, Similipecten eous. New record for South Africa: Propeamussium jeffreysii, Parvamussium formosum, Parvamussium scitulum, Cyclopecten horridus, Similipecten eous.

The faunas of the highly fossiliferous Pirabas Formation belong to the southern part of the biogeographical unit known as "Neogene Tropical America". This unit developed prior to the closure of the Central American Seaway by the Isthmus of Panama. Until now, the age of the Pirabas Formation was inferred only from biostratigraphy. The Sr-isotope (87Sr/86Sr) values of pectinid shells from the Pirabas Formation show that most parts of this unit were deposited during the Late Burdigalian (about 16-17 Ma ). This result does not contradict biostratigraphic data and it constrains the age of the Pirabas Formation more tightly than do previous estimates of age, it for future, more precise biogeographical comparisons. Fil: Martinez, Sergio. Universidad de la República; Uruguay Fil: Feijó Ramos, María Inês. Museo Paraense Emilio Goeldi; Brasil Fil: McArthur, John M.. University College London; Estados Unidos Fil: del Río, Claudia Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Thirlwall, Matthew F.. Royal Holloway University Of London; Reino Unido

Eighteen species of Pectinoidea (six Propeamussiidae Abbott, 1954, one Entoliidae Teppner, 1922, eleven Pectinidae Rafinesque, 1815) are listed from the Tarava Seamounts, Society Islands and Tuamotu Archipelago, French Polynesia. Four Propeamussiidae species (Parvamussium lamellatum n. sp., Parvamussium scutulatum n. sp., Parvamussium vesiculosum n. sp., Cyclopecten comptulus n. sp.) are new to science.

Sixty one Pectinoidea species (11 Propeamussiidae and 50 Pectinidae) collected by the 2004 Panglao Marine Biodiversity Project (PMBP) to Panglao, Philippines, and the PANGLAO 2005 Deep-Sea Cruise are described. One Propeamussiidae species is new to science: Parvamussium largoi spec. nov. Three pectinoidean species (1 Propeamus-siidae, 2 Pectinidae) are new records for the Philippines: Similipecten eous (Melvill in Melvill & Standen, 1907), "Mimachlamys" kauaiensis (Dall, Bartsch & Rehder, 1938) and Haumea rehderi (Grau, 1960). Records of species in the ZMA collection (now Naturalis Biodiversity Center) from the Philippines, not sampled by PMBP 2004 and PANGLAO 2005, are given. Amussium electrum Pelseneer, 1911 is newly synonymised with Propeamussium caducum (E.A. Smith, 1885). Type data, references, descriptions, horizontal and vertical distribution and habitat of each species are provided.

The extensive outcrops of the Late Jurassic–Early Cretaceous Vaca Muerta Formation black shales and marls in the Neuquén Basin have yielded very few bivalves, and these are not well known. The material described here was collected in central Neuquén, from late Tithonian calcareous levels within the black shales, between beds with Substeueroceras sp. and with Argentiniceras noduliferum (Steuer). The material is referred to the new genus Huncalotis and to the new species H. millaini. The strongly inequivalve shells, the ligamental area with a triangular slightly prosocline resilifer, the right valve with ctenolium and a very deep byssal notch, and the lack of radial ornamentation make the shell of this new genus strikingly similar to the Triassic pectinid Pleuronectites. This resemblance may be due to either phylogenetic relationships or convergence. Obliquipecten peruanum Rivera from central Peru is tentatively referred to Huncalotis. The Neuquén specimens are found in two main preservation types. Most of the material occurs in shell pavements, with equally abundant right and left valves and wide size range, within “beef” or “sandwich concretions”. These specimens are commonly complete but disarticulated, and show radial fractures orientated at right angles to the shell margins. A few specimens were found on the outside of large calcareous concretions within black shales; these are often articulated, complete shells, which preserve the original convexity of the valves. In some cases these articulated shells seem to be associated with large ammonite shells, suggesting an epibyssate (possibly also pseudoplanktonic) lifestyle. Die reichlich zutage tretenden Schwarzschiefer und Mergel der spätjurassisch–frühkretazischen Vaca Muerta-Formation des Neuquén-Beckens haben bisher nur sehr wenige Muscheln geliefert, die ungenügend bekannt sind. Das hier beschriebene Material wurde im Zentrum der Provinz Neuquén aufgesammelt und stammt aus kalkigen Lagen innerhalb der Schwarzschiefer des späten Tithoniums, mit den Ammoniten Substeueroceras sp. und Argentiniceras noduliferum (Steuer). Das Bivalvenmaterial wird der neuen Gattung Huncalotis mit der neuen Art H. millaini zugeordnet. Die stark ungleichklappigen Schalen ähneln aufgrund verschiedener morphologischer Charakteristika (dreieckiges leicht prosoklines Resilium im Ligamentbereich, Vorhandensein eines Ctenoliums und einer sehr tiefen byssalen Kerbe in der rechten Klappe sowie Fehlen einer radialen Ornamentierung) der triassischen pectiniden Muschelgattung Pleuronectites. Diese auffallende Ähnlichkeit kann entweder durch phylogenetische Beziehungen oder Konvergenz verursacht worden sein. Obliquipecten peruanum Rivera aus Zentral-Peru wird vorläufig ebenso der Gattung Huncalotis zugewiesen. Von den Exemplaren aus dem Neuquén-Becken wurden zwei Erhaltungstypen gefunden. Das meiste Material kommt in Muschelpflastern (mit gleichermaßen häufig vorkommenden rechten und linken Klappen sowie einem weiten Größenspektrum), in sogenannten “beef”- oder “sandwich”-Konkretionen vor. Solche Schalen sind gewöhnlich vollständig, jedoch disartikuliert und mit radial angeordneten Bruchstellen (in rechtem Winkel zum Schalenrand) versehen. Einige Exemplare wurden an der Außenseite von Kalkkonkretionen gefunden, wobei diese oft artikuliert sind und die ursprünglichen konvexen Schalen zeigen. In einigen Fällen scheinen solch artikulierte Schalen zusammen mit großen Ammonitengehäusen vorzukommen, so daß eine epibyssate (oder möglicherweise auch pseudoplanktonische) Lebensweise angenommen werden kann. Huncalotis, un enigmático nuevo género de pectinoideo (Bivalvia, Jurásico Tardío) de América del Sur. Las pelitas oscuras y margas bituminosas de la espesa Formación Vaca Muerta (Jurásico Tardío - Cretácico Temprano) se hallan ampliamente distribuidas en la cuenca neuquina pero los registros de bivalvos, y de faunas bentónicas en general, son escasos en esta unidad. El material descripto proviene de niveles fosilíferos de edad tithoniana tardía, entre niveles con Substeueroceras sp. y con Argentiniceras noduliferum (Steuer), conteniendo abundantes restos de una nueva especie de bivalvo referida al nuevo género Huncalotis. La conchilla fuertemente inequivalva, las aurículas anteriores de la valva derecha limitadas por una profunda escotadura bisal con ctenolio, el área ligamentaria con resilífero triangular y levemente prosoclino y la ausencia de ornamentación radial, hacen que las conchillas de este género sean muy similares a las del pectínido Triásico Pleuronectites. Esta similitud puede deberse a relaciones filogenéticas o simplemente a convergencia. Obliquipecten peruanum Rivera, especie de las cercanías de Lima, Perú, se incluye con dudas en Huncalotis. El material de Neuquén se halla preservado de dos modos diferentes. La mayoría se presenta como pavimentos de conchillas, con valvas derechas e izquierdas igualmente abundantes y un amplio rango de tamaños, en concreciones tipo “beef”. Estos ejemplares se hallan completos pero desarticulados, y presentan fracturas radiales perpendiculares a los márgenes de las conchillas. Otros ejemplares aparecen en el exterior de grandes concreciones calcáreas dentro de pelitas negras; éstos están comúnmente articulados, preservan la convexidad original de las valvas, y en varios casos valvas articuladas muestran estrecha relación con grandes conchillas de amonites, lo que indicaría un modo de vida epibisado, incluso pseudoplanctónico. Fil: Damborenea, Susana Ester. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina Fil: Leanza, Hector Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina

This paper describes 97 molluskan species (45 Bivalvia, 3 Scaphopoda, 49 Gastropoda) recovered from bathyal bottoms off Santa Maria di Leuca (Puglia, Italy), in the northern Ionian Sea, and provides data about their taxonomy, geographical distribution, habitat, ecological requirements and fossil record. Only 6 species remain unidentified, and all are illustrated. The bivalve-dominated assemblages belong to the so-called "cold-water coral ecosystem". They appear to depend mainly on substrate characteristics, with faunas related to hard substrate around coral-colonized mound tops, and mud-related ones in inter-mound areas, respectively. Nuculanoida and Pectinoidea among bivalves, and Conoidea and Pyramidelloidea among gastropods are the most diverse suprafamilial groups. The present paper is the first comprehensive taxonomic overview of Mediterranean bathyal mollusks including larval shell characters.

The undescribed ommatidium-like ectopic pallial eyes of three Mediterranean species of Glycymeris have been studied and compared with those of the eastern Atlantic G. glycymeris. Wide interspecific variation in eye size between the taxa is recorded with those of G. bimaculata being the largest, G. nummaria the smallest and G. pilosa and G. glycymeris of intermediate and similar dimensions. Such differences result primarily from interspecific variations in the numbers and sizes of the ommatidium-like rhabdomes. The consequences of this will be the differences in abilities to create a summed image and thereby reduce visual acuity. Other bivalves, such as the Pectinoidea, have shown eye size differences in relation to depth. Glycymeris bimaculata, with the largest eyes, occupies the shallowest depths; G. nummaria bears the smallest eyes and occupies the deepest depths. The genetically sister clusters of G. pilosa and G. glycymeris occupy intermediate depths. Accurate depth records for the four taxa blur this hypothesised trend, but comparative eye dimensions suggest it to be valid.

New shell microstructure data for the Triassic pectinid Pleuronectites reinforce shell morphological data suggesting that its family Pectinidae was derived from the superfamily Aviculopectinoidea and not from the Pernopectinidae-Entolioidesidae-Entoliidae clade. This would make the superfamily Pectinoidea, as defined by recent authors, polyphyletic. This would also imply that alivincular-alate ligaments evolved independently in the Pernopectinidae-Entolioidesidae-Entolidae and Pectinidae clades.

Twenty-nine species of Pectinoidea (12 Propeamussiidae, 1 Entoliidae, 16 Pectinidae) are recorded from the Austral Islands, the southernmost archipelago of French Polynesia. One genus (Pectinidae: Lamellipecten n. gen.) and five species (Propeamussiidae: Parvamussium australanum n. sp., Cyclochlamys australensis n. sp., Cyclopecten ambiguus n. sp.; Pectinidae: Lamellipecten aduncus n. gen., n. sp., Mimachlamys erycina n. sp.) are new to science, and most others are new records for the archipelago. The near-shore fauna of Rapa has 12 species of Pectinidae, and half of these have narrow-range distributions. Such a remarkably high level of marine endemism is shared by other mollusc taxa on Rapa.

Twenty-nine species of Pectinoidea (12 Propeamussiidae, 1 Entoliidae, 16 Pectinidae) are recorded from the Austral Islands, the southernmost archipelago of French Polynesia. One genus (Pectinidae: Lamellipecten n. gen.) and five species (Propeamussiidae: Parvamussium australanum n. sp., Cyclochlamys australensis n. sp., Cyclopecten ambiguus n. sp.; Pectinidae: Lamellipecten aduncus n. gen., n. sp., Mimachlamys erycina n. sp.) are new to science, and most others are new records for the archipelago. The near-shore fauna of Rapa has 12 species of Pectinidae, and half of these have narrow-range distributions. Such a remarkably high level of marine endemism is shared by other mollusc taxa on Rapa.

The Icelandic pectinoid fauna is reviewed, based on material from the benthic survey programme BIOICE and 17 species are recorded. Similipecten oskarssoni is proposed as a replacement name for Pecten groenlandicus var. minor Locard, 1898 (Propeamussiidae), which is considered a valid species. Lectotypes are designated for Pecten groenlandicus var. minor and Pecten frigidus Jensen, 1904 (Pectinidae). Cyclopecten ambiannulatus Schein, 1989, Parvamussium propinquum (Smith, 1885), Catillopecten eucymatus (Dall, 1898), and Aequipecten opercularis (Linnaeus, 1758) were previously not known from the Icelandic fauna. All species are figured and described and distinguishing characters are discussed. The distribution in Scandinavian and North Atlantic waters is revised based on the collections in SMNH. The low frequency of juvenile specimens of A. opercularis, Mimachlamys varia and Pecten maximus may indicate that Scandinavian populations are the result of very occasional recruitment.

The Icelandic pectinoid fauna is reviewed, based on material from the benthic survey programme BIOICE and 17 species are recorded. Similipecten oskarssoni is proposed as a replacement name for Pecten groenlandicus var. minor Locard, 1898 (Propeamussiidae), which is considered a valid species. Lectotypes are designated for Pecten groenlandicus var. minor and Pecten frigidus Jensen, 1904 (Pectinidae). Cyclopecten ambiannulatus Schein, 1989, Parvamussium propinquum (Smith, 1885), Catillopecten eucymatus (Dall, 1898), and Aequipecten opercularis (Linnaeus, 1758) were previously not known from the Icelandic fauna. All species are figured and described and distinguishing characters are discussed. The distribution in Scandinavian and North Atlantic waters is revised based on the collections in SMNH. The low frequency of juvenile specimens of A. opercularis, Mimachlamys varia and Pecten maximus may indicate that Scandinavian populations are the result of very occasional recruitment.

The unique, double-retina, concave mirror eyes of scallops are abundant along the valve mantle margins. Scallops have the most acute vision among the bivalve molluscs, but little is known about how eyes vary between scallop species. We examined eye morphology by immunofluorescent labeling and confocal microscopy and calculated optical resolution and sensitivity for the swimming scallops Amusium balloti (Bernardi, 1861), Placopecten magellenicus (Gmelin, 1791), Argopecten irradians (Lamarck, 1819), Chlamys hastata (Sowerby, 1842), and Chlamys rubida (Hinds, 1845) and the sessile scallops Crassadoma gigantea (Gray, 1825) and Spondylus americanus (Hermann, 1781). We found that eye morphology varied considerably between scallop species. The eyes of A balloti and P. magellenicus had relatively large lenses and small gaps between the retinas and mirror, making them appear similar to those described previously for Pecten maximus (Linnaeus, 1758). In contrast, the other five species we examined had eyes ...

Two types of multi-cellular eyes have been identified in the Bivalvia. Paired cephalic eyes occurring internally above the anterior end of the ctenidia are seen only in representatives of the Arcoidea, Limopsoidea, Mytiloidea, Anomioidea, Ostreoidea, and Limoidea. These eyes, comprising a pit of photo-sensory cells and a simple lens, are thought to represent the earliest method of photoreception. Many shallow-water marine, estuarine, and freshwater bivalves also possess simple photoreceptive cells in the mantle that enable them to respond to shadows. In some other marine, shallow-water taxa, however, a second type of more complex photoreceptors has evolved. These comprise ectopic pallial eyes that can be divided into three broad categories, in terms of their locations on the (i) outer mantle fold in representatives of the Arcoidea, Limopsoidea, Pterioidea, and Anomioidea, (ii) middle fold in the Pectinoidea and Limoidea, and (iii) inner fold in the Cardioidea, Tridacnoidea, and Laternulidae (Ano...

This paper lists 22 pectinoid types (21 primary and one secondary) and three potential syntypes in the Museum of Natural History (ZMB) in Berlin. Eight lectotypes are designated herein for the stabilization of taxonomic names: Pecten aequatorialis, Pecten australis, Pecten clathratus, Camptonectes gaussianus, Pecten nigromaculatus, Pecten puncticulatus, Pecten pycnolepis and Pecten vesiculosus. Nomenclatural notes on the types and further specimens are provided and the current systematic positions of the covered taxa are reported.

Five species of epibenthic pycnogonids collected on the giant lion´s-paw scallop Nodipecten subnodosus are recorded. A new species of Eurycyde, Eurycyde bamberi, is described. Of the 19 species known in this genus; the new species is closest to Eurycyde hispida Kroyer, 1844 but differs from it in the absence of plumose spines and the shapes of the lateral process, first coxa, and ocular tubercle. The new species represents the third member of Eurycyde from the eastern Pacific in addition to Eurycyde spinosa Hilton, 1916 and Eurycyde clitellaria Stock, 1955. Besides Eurycyde bamberi, the following species were collected: Nymphopsis duodorsospinosa Hilton, 1942c; Callipallene californiensis (Hall, 1913); Nymphon lituus Child, 1979; and Pycnogonum rickettsi Schmitt, 1934. Pycnogonum rickettsi is recorded for first time from Mexican waters, as is Nymphon lituus from the western coast of Baja California Peninsula. Each of these four species are re-described and re-illustrated in order to fill in existing gaps in the literature of the region.

This paper addresses the systematics of Pectinoidea collected in the northeast Atlantic on the Lusitanian seamounts, on Galicia Bank, and on the Meteor group seamounts. There are 21 species recorded, of which three (Parvamussium intuslaevis, Cyclopecten cincinnatus, Cyclopecten vimineus from the Meteor group seamounts) are described as new. A lectotype is designated for Propeamussium lucidum (Jeffreys in Thomson, 1873). Cyclopecten antiquatus (Philippi, 1844) is for the first time recorded alive at 805–1160 m on the Meteor group and Galicia seamounts, and distinguished from the Mediterranean–eastern Atlantic species C. hoskynsi (Forbes, 1844). Bathypecten Schein‐Fatton, 1985, is placed in synonymy of Catillopecten Iredale, 1939, and the relevant North Atlantic species accordingly named Catillopecten eucymatus (Dall, 1898) (comb. nov.). The character regarding the development of internal ribs, traditionally considered to diagnose Parvamussium and Cyclopecten, is here shown to conflict with characters of th...

Eight calcite layers of bivalves are examined in the view of QTA. We use the QTAinformation to compare calcite prisms of a fossil species, Trichite , with other outer prismatic calcitelayers. The results indicate that the fossil species exhibit textures close to the ones of Pteriomorphia,but considerably different from the ones of mytilids, as expected from molecular analysis. Textureanalysis results point out that inside the Pterioids, the Pectinoidea family is probably more distantthan Pterioidea and Pinnoidea ones, coherently with other studies, and perhaps closer to Mytiloidea.However, texture analysis seems to favour a closer relationship of Trichites with Pinnoids than withPteriids. Introduction Modern bivalved molluscs make their calcareous shells out of layers of two or more of thefollowing microstructures (aragonitic prisms, nacre, crossed-lamellar, complex crossed-lamellar andhomogeneous, and, or calcitic prisms and foliae). There is good evidence that the earliest bivalves,recorded from the Middle Cambrian, which were wholly aragonitic, comprising a thin outer layer ofprisms and a substantially thicker layer of nacre [1,2], and that the diversity of microstructures aroserelatively rapidly, most by the Ordovician [3]. Quite why this diversity of structures evolved isunclear but raises extremely interesting questions as to the potential benefits of the more derivedmicrostructures. What is well established is that the microstructural arrangements shown bydifferent bivalve taxa is of considerable phylogenetic value [4,5,6].Of particular interest is the evolution of calcitic microstructures from the originally whollyaragonitic primitive shell. Calcitic microstructures are found in only two of the subclasses of theBivalvia: the Pteriomorphia and the Heteroconchia. In each of these subclasses calcite prisms arefound in two apparently separate clades and it is thus entirely reasonable to suggest this mineralogyhas evolved on at least four separate occasions [7,8]. Within the Heteroconchia, outer layers ofcalcite prisms characterise the rudists, large, bizarre extinct bivalves which dominated shallowmarine carbonate platforms for much of the Mesozoic, and also occur in some members of theChamidae, an extant family of tropical bivalves [8]. Within the Pteriomorphia, a large clade ofcalcite secreters, the pterioids, includes major groups such as the oysters, scallops, pinnoids andpteriids, many of which have expanded their calcitic layers such that they may account for most ofthe shell thickness. This expansion of the calcitic shell layers is most extreme in the oysters wherethe only aragonite present is restricted to the muscle attachment sites and ligament [9]. The otherpteriomorphian group to have some members to secrete calcite is the mytiloids (mussels). In boththe chamids and mytiloids, however, there is clear evidence that not all members secrete calcite,implying that even within these taxa the ability to secrete calcite has evolved more than once.The study of crystallographic textures in gastropods has revealed that this may be a method ofrevealing phylogenetic relationships [10]. It may be instructive to study bivalve microstructures inthe same way. This paper focuses on a QTA study of the calcite prisms of a number of modernpteriomorph bivalves. Specifically, we examined and compared calcite prisms from two mytilids

Of the 29 species of Pectinidae here recorded from South Africa and Mozambique, ca. 76% have Indo-West Pacific origins, 17% are of Mediterranean-West African origin and ca. 7% are probably of Southern Ocean origin. New species: Mirapecten tuberosus, Veprichlamys africana. New subspecies: Aequipecten commutatus peripheralis. New synonyms: Chlamys liltvedi Wagner, 1984 = Laevichlamys lemniscata(Reeve, 1853). Genus Karnekampia Wagner, 1988 = Pseudamussium Mörch, 1853, Somalipecten Waller, 1996 = Mirapecten Dall, Bartsch & Rehder, 1938. Perapecten Wagner, 1985, and Lindapecten Petuch, 1995 = Aequipecten Fischer, 1886. New records for South Africa: Delectopecten musorstomi Poutiers, 1981; Anguipecten picturatus Dijkstra, 1995; Decatopecten amiculum (Philippi, 1851); D. plica (Linnaeus, 1758); Glorichlamys elegantissima (Deshayes, 1863); Gloripallium pallium (Linnaeus, 1758); Juxtamusium maldivense (Smith, 1903); Laevichlamys deliciosa (Iredale, 1939), L. lemniscata (Reeve, 1853); Pedum spondyloideum (Gmelin, 1791); Semipallium crouchi (Smith, 1892); S. flavicans (Linnaeus, 1758); Haumea minuta (Linnaeus, 1758). New combinations: Chlamys gilchristi Sowerby, 1904, to Pseudamussium; Chlamys weberi Bavay, 1904, to Laevichlamys; Pecten coruscans Hinds, 1845, to Semipallium; Chylams [sic] humilis Sowerby, 1904, and Ostrea multistriata Poli, 1795, to Talochlamys. Lectotypes designated: Pallium striatum Schumacher, 1817; Pecten velutinus Sowerby, 1842; Pecten strangei Reeve, 1852.

Nineteen species of Pectinoidea (16 Propeamussiidae, 3 Pectinidae) are herein listed. All species from the Solomon Islands (9 species), and New Caledonia (Norfolk Ridge [7], main island of New Caledonia [1], Grand Passage [1], Coral Sea [1]) are new records. Two Propeamussiidae species are new to science: Parvamussium orbiculatum n. sp. (Solomon Islands and Coral Sea) and Parvamussium perspicuum n. sp. (Vanuatu). One pectinid species from Vanuatu (Juxtamusium sp.) will be described later, when more material becomes available.

Pteriomorphian spermatozoa. Like those of most other bivalves, are of the classic aquasperm type (conical acrosomal vesicle, short to rod-shaped nucleus, short midpiece composed of two centrioles and a ring of spherical mitochondria, a simple flagellum). Whereas most other bivalve subclasses show at least some defining acrosomal feature(s). this does not appear to be the case within the Pteriomorphia. While this could indicate non-monophyletic status, it also correlates with the fact that the Pteriomorphia are very old and very successful group of bivalves. Acrosomal similarities suggest a close link between the Ostreoidea and Limoidea (acrosomal vesicle with wedge-shaped apical zone: radiating plates present but not well developed): and between the Pterioidea, Pinnoidea and Pectinoidea (dense anterior layer: very well developed radiating plates). For supposedly closely related taxa, the Arcoidea and Limopsoidea (both Arcoida) differ markedly I;om each other in acrosomal shape and substructure. The affinities of the Anomioidea and even more so the Mytiloida remain uncertain, the latter possibly connected with the Pterioida or, more likely, removed from the rest of the Pteriomorphia (mytiloid acrosomes show concentric lamellae). A very close relationship between the Pectinidae and Spondylidae of the Pectinoidea is demonstrated (dense anterior layer of acrosome recurved). Within the Mytilidae (Mytiloidea) there is substantial variation in sperm morphology between supraspecific taxa especially at the subfamial level.

In March 2004, eight pectinoidean species (7 Pectinidae and one Propeamussiidae) are collected by scuba-diving from Bonaire (Netherlands Antilles), of which five are new records (Pectinidae: Decatopecten antillarum, Euvola chazaliei, Laevichlamys multisquamata, Spathochlamys benedicti; Propeamussiidae: Similipecten nanus).

Thirty five species of Pectinoidea (33 Pectinidae, 2 Propeamussiidae) are described from Hansa Bay, Papua New Guinea. Serratovola pallula n. sp. is here introduced as new to science. Lectotypes are designated of Pecten cloacatus Reeve, 1853 and Pecten tricarinatus Anton, 1838, and type localities are designated for Pecten vexillum Reeve, 1853, Pecten spectabilis Reeve, 1853, and Ostrea squamosa Gmelin, 1791.

The report is based on a collection of 344 samples of pectinoids from the Red Sea and adjacent waters. Four species of Propeamussiidae and 18 species of Pectinidae were recognized. One pectinid taxon, Mirapecten yaroni, is undescribed. Three taxa are new pectinid records for the area: Delectopecten musorstomi Poutiers, 1981, Glorichlamys quadrilirata (Lischke, 1870), and Mimachlamys andamanica (Preston, 1908). Gloripallium pallium (Linnaeus, 1758) is recorded as living in the area for the first time. Lectotypes are designated for Similipecten eous (Melvill in Melvill & Standen, 1907) Decatopecten flabelloides (Reeve, 1852), Coralichlamys madreporarum (G.B. Sowerby 2nd., 1842) and Semipallium crouchi (Smith, 1892). Type localities of 20 taxa and the depository of type material for 19 taxa a re given. All taxa are figured and extensive synonymy is presented. Intraspecific variation of most taxa is described. The total geographic distribution of each taxon is outlined. The following taxa may be ende...

Twenty-four pectinoidean species are recorded from Lord Howe Island (7 species), Norfolk Island (13 species) and the Kermadec Islands (14 species). Eighteen species are new records, and these are compared with similar species from the Australasian region. The following taxa are newly synonymised: Annachlamys leopardus rena Iredale, 1939 (= A. kuhnholtzi (Bernardi, 1860)), Chlamys cellularis Oliver, 1915 (= C. c. coruscans (Hinds, 1845)), Chlamys (Mimachlamys) asperrimoides Powell, 1958 (= M. senatoria (Gmelin, 1791)). Chlamydella favus lemchei Powell , 1958 is considered to be specifically distinct from Cyclopecten favus Hedley, 1902, and is referred to Cyclochlamys Finlay, 1926. Lectotypcs are for the following species designated: Hemipecten forbesianus A. Adams & Reeve, 1849, Ostrea senatoria Gmelin, 1791, and Ostrea porphyrea Gmelin, 1791.

Sixty one Pectinoidea species (11 Propeamussiidae and 50 Pectinidae) collected by the 2004 Panglao Marine Biodiversity Project (PMBP) to Panglao, Philippines, and the PANGLAO 2005 Deep-Sea Cruise are described. One Propeamussiidae species is new to science: Parvamussium largoi spec. nov. Three pectinoidean species (1 Propeamus-siidae, 2 Pectinidae) are new records for the Philippines: Similipecten eous (Melvill in Melvill & Standen, 1907), "Mimachlamys" kauaiensis (Dall, Bartsch & Rehder, 1938) and Haumea rehderi (Grau, 1960). Records of species in the ZMA collection (now Naturalis Biodiversity Center) from the Philippines, not sampled by PMBP 2004 and PANGLAO 2005, are given. Amussium electrum Pelseneer, 1911 is newly synonymised with Propeamussium caducum (E.A. Smith, 1885). Type data, references, descriptions, horizontal and vertical distribution and habitat of each species are provided.

The geographic distribution of Recent taxa is important in interpreting paleobiogeography and the fossil record of extinction. We examine the latitudinal diversity gradient in Recent marine bivalve molluscs and the effects of bivalve distributional patterns on the severity of model extinctions using a global biogeographic database for genera of Recent shallow (

Ten species of the genus Spondylus are recorded from South Africa and Mozambique (6 from South Africa, 9 from Mozambique). Of these, only Spondylus nicobaricus Schreibers , 1793, has been reported previously. Spondylus groschi from Mozambique and Natal is described as new. The remainder are widely distributed Indo-Pacific taxa: Spondylus cuneus Reeve, 1856, Spondylus sinensis Schreibers, 1793, Spondylus Occidens Sowerby, 1903, Spondylus sanguineus Dunker, 1852, Spondylus castus Reeve, 1856, Spondylus butleri Reeve, 1856, Spondylus flabellum Reeve, 1856, and Spondylus tenuispinosus Sowerby, 1847.

This paper documents the species of Pectinoidea Rafinesque, 1815 collected in Vanuatu during the SANTO 2006 expedition. A total of 49 species (13 Propeamussiidae Abbott, 1954, 4 Cyclochlamydidae n. fam., 1 Entoliidae Teppner, 1922, and 31 Pectinidae Rafinesque, 1815) are represented, of which 70% are new records for Vanuatu. A new family, Cyclochlamydidae n. fam., is established for the genera Cyclochlamys Finlay, 1926, Chlamydella Iredale, 1929 and Micropecten n. gen., formerly placed in Propeamussiidae, but differing by their sculptured prodissoconch (smooth in Propeamussiidae), an occasionally antimarginally sculptured right valve (smooth or weak commarginally sculptured in Propeamussiidae), a (common) simple outer prismatic layer of longitudinally hexagonal microstructure on the right valve (an outer layer of columnar calcite in Propeamussiidae). The family Cyclochlamydidae n. fam. includes about 30 species, all with adult size in the 1.2-6 mm range, and living mainly in the Southern Hemisphere and Indo-West Pacific; the family is not known from the Arctic, the Atlantic, or the northern and eastern Pacific. One new genus, Micropecten n. gen., and two new species, Cyclochlamys aperta n. sp. and Micropecten excuratus n. gen., n. sp., are described.

During identification of bivalve molluscs collected in Antarctica, a rich taxonomic bibliography was gathered, stimulating comparisons with the Brazilian malacofauna. We listed a total of 68 and 368 known shallow-water species (less than 200 m depth) from Antarctica and Brazil, respectively, in order to find species, families and superfamilies in common, and to investigate how these malacofaunas differ in regard to these representative groups and their life habits. There are 23 superfamilies absent in Antarctica, but present in Brazil with at least one species; the reverse does not occur, as all superfamilies known from Antarctica are also recorded from Brazil. The number of Brazilian species is higher, being composed of a mixture of taxa from different biogeographical provinces, whereas in Antarctica there are only a few species adapted to its polar conditions, with minor components from elsewhere. Thus, many typical Caribbean species extend into Brazil, belonging to the diverse Arcoidea, Pectinoidea, Lucinoidea, Cardioidea, Veneroidea, and Tellinoidea. Cemented Ostreoidea, Plicatuloidea, Dimyoidea, Spondylidae (Pectinoidea), and Chamoidea are absent from Antarctica, as are wood (Teredinidae, Pholadoidea) and rock borers (Pholadidae, Pholadoidea; Gastrochaenoidea; and Lithophaginae, Mytiloidea). A large number of Brazilian species of infaunal (e.g., Tellinidae, Veneridae, Cardiidae, and Mactroidea) and epifaunal groups (Pectinidae, Mytilidae, and Arcidae) are absent from or poorly represented in Antarctica. Nuculanoidea, Limopsoidea, Lucinoidea, Galeommatoidea, Cyamioidea, and Cuspidarioidea are the richest groups in Antarctica; some of them are also represented by several species in Brazil, albeit in deeper waters. Three species are recorded as living in both places: Limatula pygmaea (Limidae), Lasaea adansoni (Lasaeidae), and Gaimardia trapesina (Gaimardiidae). Through the analysis of these groups from each fauna, it is possible to identify those that are taxonomically diverse in one place or another, and then emphasize them in ecological studies, eventually using them as model or monitoring organisms. The present paper can be a starting point for future discussion on the existing latitudinal gradients along the coast of eastern South America, stimulating studies on changes occurring in the composition of the faunas of bivalves from Brazil, Uruguay, Argentina, and Antarctica. Durante a identificação de moluscos bivalves coletados na Antártica, foi reunida uma rica bibliografia taxonômica, estimulando comparações com a malacofauna do Brasil. Assim, listamos um total de 68 espécies conhecidas para águas rasas (menos de 200 m de profundidade) da Antártica e 368 para o Brasil, procurando encontrar espécies, famílias e superfamílias em comum a ambos os locais, e investigando em que essas malacofaunas diferem em relação aos grupos representados e em relação ao hábito de vida das suas espécies. Vinte e três superfamílias não possuem representantes antárticos, mas estão presentes com pelo menos uma espécie brasileira; o oposto não ocorre, pois todas superfamílias que ocorrem na Antártica também são conhecidas para o Brasil. O número de espécies brasileiras é maior, composto por uma mistura de táxons de diferentes províncias biogeográficas, enquanto na Antártica existem somente poucas espécies adaptadas às condições polares, com uma minoria de representantes de fora da Antártica. Dessa forma, muitas espécies típicas do caribe se distribuem até o Brasil, pertencendo aos diversos Arcoidea, Pectinoidea, Lucinoidea, Cardioidea, Veneroidea e Tellinoidea. Cimentantes Ostreoidea, Plicatuloidea, Dimyoidea, Spondylidae (Pectinoidea) e Chamoidea não estão presentes na Antártica, como também não estão perfuradores de madeira (Teredinidae, Pholadoidea) e de rochas (Pholadidae, Pholadoidea; Gastrochaenoidea; e Lithophaginae, Mytiloidea). É notável o grande número de espécies brasileiras de grupos infaunais (exemplos, Tellinidae, Veneridae, Cardiidae e Mactroidea) e epifaunais (Pectinidae, Mytilidae e Arcidae), que são ausentes ou pobremente representados na Antártica. Nuculanoidea, Limopsoidea, Lucinoidea, Galeommatoidea, Cyamioidea e Cuspidarioidea são os grupos mais ricos em espécies antárticas, alguns deles também sendo especiosos no Brasil, entretanto, em maiores profundidades. Três espécies são registradas para ambos os locais: Limatula pygmaea (Limidae), Lasaea adansoni (Lasaeidae) e Gaimardia trapesina (Gaimardiidae). Através de análises dos grupos, é possível apontar aqueles que são taxonomicamente diversos em uma ou outra fauna, e então enfatizá-los em estudos ecológicos, utilizando-os como "organismos monitores" ou modelos. O presente trabalho pode ser um ponto de partida para futuras discussões sobre a ocorrência de um gradiente latitudinal ao longo da costa leste da América do Sul, estimulando trabalhos sobre mudanças que ocorrem na composição das faunas de bivalves do Brasil, Uruguai, Argentina e Antártica.

Twenty-nine species of Pectinoidea (12 Propeamussiidae, 1 Entoliidae, 16 Pectinidae) are recorded from the Austral Islands, the southernmost archipelago of French Polynesia. One genus (Pectinidae: Lamellipecten n. gen.) and five species (Propeamussiidae: Parvamussium australanum n. sp., Cyclochlamys australensis n. sp., Cyclopecten ambiguus n. sp.; Pectinidae: Lamellipecten aduncus n. gen., n. sp., Mimachlamys erycina n. sp.) are new to science, and most others are new records for the archipelago. The near-shore fauna of Rapa has 12 species of Pectinidae, and half of these have narrow-range distributions. Such a remarkably high level of marine endemism is shared by other mollusc taxa on Rapa.

Fifty-two deep-water species of Pectinoidea (37 Propeamussiidae, 1 Entoliidae, 14 Pectinidae) are listed from Norfolk Ridge (11 species), Loyalty Islands (4 species), Fiji Islands (30 species), Tonga (26 species), Solomon Islands (26 species) and the Marquesas archipelago (8 species). All species from Fiji, Tonga and the Marquesas are new records and six species of Propeamussiidae are new to science: Propeamussium boucheti (Fiji and Tonga), Parvamussium biformatum (Solomons), Parvamussium lozoueti (Fiji and Tonga), Parvamussium marquesanum (Marquesas), Parvamussium polynesianum (Marquesas) and Similipecten herosae (Tonga). Two new combinations (Hyalopecten tydemani, Talochlamys gladysiae) are introduced.

A further specimen of the rare allochthonous scallop Chlamys lischkei was found at Schiavonea di Corigliano Calabro, Gulf of Corigliano (Cosenza), while SCUBA diving at a depth of about 30 m on a muddy detritic bottom. This new single record, the third for the entire Mediterranean Sea and the second for the Italian Seas, confirms the sporadic presence, often believed uncertain, of this species in the Mediterranean Sea.

The Pectinoidea species collected on the coral reefs around the Berau Islands (East Kalimantan, Indonesia) were studied. Nineteen species (four Propeamussiidae, fifteen Pectinidae) are listed from the Berau Islands. Three pectinoidean species are new to science, of which two are described herein: Parvamussium caesicium n. sp. and Talochlamys inaequalis n. sp. Two pectinid species (Pascahinnites coruscans coruscans and Palliolum minutulum) are new records for Indonesia.