Trophonella (Gastropoda: Muricidae), a New Genus from Antarctic Waters, with the Description of a New Species

The new genus Trophonella is described from the outer shelf and upper continental slope of Antarcticaand islands within the Antarctic Convergence. Four previously known species that had been attributed to the genusTrophon (Trophon scotianus Powell, 1951; T. echinolamellatus Powell, 1951; T. enderbyensis Powell, 1958; and T.eversoni Houart, 1997) are included in Trophonella, as is one new species (Trophonella rugosolamellata) describedherein. Trophonella resembles Trophon in gross shell morphology: the members of both genera have large, globoseshells, paucispiral protoconchs, prominent axial lamellae, and short siphonal canals. Trophonella differs fromTrophon in having shells with evenly rounded whorls that lack a well-defined shoulder; rachidian teeth withdistinctive, broadly triangular central cusps, but that lack the marginal cusps of Trophon; characteristic sphericalaccessory salivary glands; and a circumpapillar fold on the penis that is absent in Trophon. Relationships of thegenera Trophon and Trophonella, as well as of the subfamily Trophoninae are reexamined by supplementing the datamatrix of Kool (1993b, Table 3) with data for additional taxa. Results support the segregation of Trophonella fromTrophon at the generic level. Based on the relationships of the type species of their respective nominotypical genera,Trophoninae is either the sister taxon of a narrowly circumscribed Ocenebrinae, or both are part of a larger clade. Abetter resolved phylogeny containing a much broader sampling of the more than 50 genus-level taxa that have beenattributed to these two subfamilies will be required in order to delineate more precisely the membership of the cladeand to identify its diagnostic synapomorphies.Fil: Harasewych, M. G.. National Museum of Natural History; Estados UnidosFil: Pastorino, Roberto Santiago Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

The Recent Introduction of a Freshwater Asiatic Bivalve, Limnoperna forlunei (Mytilidae) into South America

The temporal and spatial distribution of Limnoperna forlunei in the Argentine littoral of the Rio de la Plata is reported. Its distribution is limited by the most contaminated area and by an increment in the saline concentration. A decrease in density was recorded between August 1992 and January 1993. Subsequently there was an increase in density up to a maximum of 82,000 ind-m-2 in May 1993. It is concluded that because of its functional and morphological characteristics. L. fortuna will spread quickly. With Corbicuia fluminea and C. largitherti, Limnoperma fortunei is the third invading species to be introduced into South America from Southeast Asia. Its possible entry into Argentina, by trading ships from Korea and Hong Kong, is suggested. Import peaks correspond with the estimated arrival of these three invaders.Facultad de Ciencias Naturales y Muse

Cenozoic Ampullinidae and Naticidae (Mollusca, Gastropoda) from Patagonia, Argentina

A revision of the Cenozoic Ampullinidae and Naticidae from a wide range of localities and stratigraphic units in Patagonia revealed the occurrence there of thirteen species referable to these families. Ampullinid species described are Tejonia? tapia (Feruglio, 1935); Tejonia arroyoensis n. sp. and Pseudamaura dubia (Petersen, 1946). Naticids are represented by the following valid species: ‘‘Natica’’ entreriana Borchert, 1901; Euspira patagonica (Philippi, 1845); Notocochlis borrelloi (Brunet, 1995); Bulbus subtenuis (Ihering, 1897); Polinices santacruzensis Ihering, 1907; Polinices puntarenasensis Ihering, 1907; ‘‘Polinices’’ ortmanni Ihering, 1907 (nomen dubium); Polinices mina n. sp.; Glossaulax secundum (Rochebrune and Mabille, 1885); and Darwinices claudiae n. gen. n. sp.Facultad de Ciencias Naturales y Muse

Cenozoic Ampullinidae and Naticidae (Mollusca, Gastropoda) from Patagonia, Argentina

A revision of the Cenozoic Ampullinidae and Naticidae from a wide range of localities and stratigraphic units in Patagonia revealed the occurrence there of thirteen species referable to these families. Ampullinid species described are Tejonia? tapia (Feruglio, 1935); Tejonia arroyoensis n. sp. and Pseudamaura dubia (Petersen, 1946). Naticids are represented by the following valid species: ‘‘Natica’’ entreriana Borchert, 1901; Euspira patagonica (Philippi, 1845); Notocochlis borrelloi (Brunet, 1995); Bulbus subtenuis (Ihering, 1897); Polinices santacruzensis Ihering, 1907; Polinices puntarenasensis Ihering, 1907; ‘‘Polinices’’ ortmanni Ihering, 1907 (nomen dubium); Polinices mina n. sp.; Glossaulax secundum (Rochebrune and Mabille, 1885); and Darwinices claudiae n. gen. n. sp.Facultad de Ciencias Naturales y Muse

Two new deep-sea muricids (Gastropoda) from Argentina

Two new species of muricids belonging in the genus Trophonare described from the upper slope off the Atlantic coast ofArgentina. Both species have a small size for the genus. Theradulae show similarities with those of Antarctic species of thesame genus. Trophon columbarioides new species has a smoothshell with spines pointed adapically and was collected at 37–38°S, in 209–382 m. Trophon fasciolarioides new species hasprominent spiral cords and was collected at Burwood Bank in286–292 m depth and off Bahía Blanca in ca. 1000 m depth.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"; ArgentinaFil: Scarabino, Fabrizio. Ministerio de Educación y Cultura. Museo Nacional de Historia Natural; Urugua

The family Caecidae (Gastropoda: Caenogastropoda) in Argentine waters

This is the first formal report of members of the family Caecidae in Argentine waters. Caecum striatum de Folin, 1868, C. strigosum de Folin, 1868, and C. achirona (de Folin, 1867) are re-described from shallow waters off Piedras Coloradas ( 4053.0810 S, 6507.5920 W), Rı´o Negro Province, Argentina. This is the farthest south record of these species which were previously recorded from USA, Bahamas, Panama, Brazil, and Uruguay. The authors also make observations about the different ontogenetic stages of the studied species. Scanning electron microscope illustrations of radula and operculum are provided for the first time.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"; ArgentinaFil: Chiesa, Ignacio Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

New taxonomic position and neotype designation for the conoidean gastropod Pleurotoma patagonica d’Orbigny, 1841

Pleurotoma patagonica d’Orbigny, 1841 has been placed in several genera and families since its original description, perhaps because the type material, presumed lost, was never revised after the original description and because of the chaotic systematics of conoidean gastropods. New specimens, matching the original description and illustration and collected near the type locality allowed us to study the radula, shell, and protoconch. A neotype designation is proposed for this species in order to fix its identity. We tentatively assign it to the mangeliid genus Bela Leach, 1847, thus establishing Bela pata-gonica (d’Orbigny, 1841) comb. nov. Eleven species of Bela have been reported from Argentine waters; however, all of them have been reclassified into other genera and even other families. Despite the appar-ent geographic distance of B. patagonica comb. nov. from other species of this genus, this taxonomic placement of this species seems most appropriate and emphasizes shell characters until molecular data become available.Fil: Sánchez, Noelia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Pastorino, Roberto Santiago Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

A taxonomic revision of the genus Trochita Schumacher, 1817(Gastropoda: Calyptraeidae) from the southwestern Atlantic

The authors revised the Atlantic species of the genusTrochita.Two valid species are recognized.Trochita pileus(Lamarck,1822) andT. pileolus(d’Orbigny, 1841) are redescribed andthe type material of each species is illustrated. Both speciesrange from the coast of Buenos Aires province to Tierra delFuego.Trochita pileusis a common subtidal Patagonian speciesandT. pileolusis rare and usually lives in deeper waters.Trochita trochiformisa Pacific only species is compare with theAtlantic representatives. Protoconch ornamentation and septummargin are the main differences between both Atlantic species.Trochita georgianaPowell is a junior synonym ofT. pileolus.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”; ArgentinaFil: Urteaga, Diego Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

Phenotypic Differentiation of Ecologically Significant Brachidontes Species Co-Occurring in Intertidal Mussel Beds from the Southwestern Atlantic

Fil: Adami, Mariana Laura. División Zoología Invertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Pastorino, Guido. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia. Ciudad Autónoma de Buenos Aires; ArgentinaFil: Orensanz, J.M.. Centro Nacional Patagónico (CENPAT- CONICET). Puerto Madryn. Chubut; Argentin

Some remarks on the gross anatomy of Adelomelon ferussacii (Donovan, 1824) (Gastropoda: Volutidae) from the coast of Patagonia, Argentina

Specimens of the volutid Adelomelon ferussacii (Donovan,1824) were dissected. These were collected during an extraordinarylow tide on February, 2006, at Playa La Mina, Puerto SanJulia´n, Santa Cruz Province, Argentina (49090 S, 67370 W).The gross anatomy, along with radulae and shell ultrastructure,are described for the first time. Analysis of these features suggestsa close relationship with the other species of the genusAdelomelon Dall, 1906, and raises doubts about the validityof Pachycymbiola Ihering, 1907, a genus in which it has beenincluded by recent authors.Fil: Segade Enrique, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Pastorino, Roberto Santiago Guido. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin