Primer registro formal del quitón incubador Calloplax vivipara (Polyplacophora: Callistoplacidae) en Perú

Calloplax vivipara (Plate, 1899) se registra formalmente por primera vez en el litoral sur peruano. Cuatro ejemplares fueron encontrados en el intermareal pedregoso debajo de bloques de piedras en Islay, Arequipa, en diciembre de 2013 y octubre de 2019. Una hembra de 9.2 mm de longitud del cuerpo colectada en la primavera del 2013 presentó seis juveniles en la parte externa de la zona de inserción de los ctenidios en el surco paleal, constituyendo el primer caso de un quitón incubador en Perú.

Calloplax vivipara (Plate, 1899) is formal recorded for the first time in the southern Peruvian coast. Four specimens were found in rocky intertidal environment under blocks of stones in Islay, Arequipa, in December 2013 and October 2019. A female of 9.2 mm body length collected in the spring of 2013 presented six juveniles in the external part of the insertion zone of the ctenidia in the pallial groove, constituting the first case of an incubating chiton in Peru.

First inventory of benthic mollusks associated with the reef ecosystems of Morro de São Paulo on Tinharé Island in northeastern Brazil / Primeiro inventário de moluscos bentônicos associados aos ecossistemas recifais do Morro de São Paulo na Ilha Tinharé, nordeste do Brasil

Abstract: The reef ecosystems of Morro de São Paulo are located in the Tinharé-Boipeba Environmental Preservation Area which was established in 1992 in the state of Bahia, Brazil. Despite this area has been created more than two decades ago, no study has provided knowledge on the invertebrate biodiversity associated with such reef ecosystems. The present investigation provides the first inventory of benthic mollusks associated with the reef ecosystems of Morro de São Paulo based on the collection of living specimens and fresh empty as well as some worn shells. Mollusks were sampled in January 2015 and August 2016 through intensive searches from the intertidal to shallow subtidal habitats of the reefs on three beaches of Morro de São Paulo. Taxonomic richness and biodiversity indices were analyzed. This rapid assessment of the malacofauna resulted in the determination of 84 species belonging to 44 families of gastropods as well as 13 species belonging to eight families of bivalves and one chiton (total: 98 species). Species richness was numerically dominated by members of the subclass Caenogastropoda. The families with the largest number of species were Ranellidae (5), Muricidae (6) and Marginellidae (7). Conus regius, Cypraecassis testiculus, Lobatus goliath, Strombus pugilis, Tonna galea, Turbinella laevigata and Vasum cassiforme are extremely vulnerable macrospecies in the region due to their commercial importance. Comparisons of the malacofauna composition between the study site and Abrolhos Bank were made from data published for this region. ACE and CHAO 1 estimated 133 mollusk species for the region. Despite the rapid assessment, the number of species discovered in the study area approached 73.6% of the estimated total number. The considerable number of mollusk species found in a relatively small area with insufficient sampling underscores the importance of the reef ecosystems of Morro de São Paulo as a one priority area for conservation on the coast of the state of Bahia, Brazil, for which the species richness of other invertebrate groups is virtually unknown.

Resumo: Os ecossistemas recifais do Morro de São Paulo estão na área de proteção ambiental Tinharé-Boipeba, a qual foi estabelecida em 1992 no estado da Bahia, Brasil. Apesar desta área ter sido criada há mais de duas décadas, nenhum estudo foi realizado sobre a biodiversidade de invertebrados associados a tais ecossistemas recifais. Este trabalho representa o primeiro inventário de moluscos bentônicos associados aos ecossistemas recifais do Morro de São Paulo com base na coleta de indivíduos vivos e conchas com superfície íntegra e desgastada. Moluscos foram amostrados em janeiro de 2015 e agosto de 2016 através de busca ativa em habitats das regiões entremarés e sublitoral dos ecossistemas recifais nas três praias do Morro de São Paulo. A riqueza taxonômica e índices de biodiversidade foram analisados. O inventário da malacofauna resultou na identificação de 84 espécies pertencentes a 44 famílias de gastrópodes bem como 13 espécies pertencentes a oito famílias de bivalves e um quiton (total: 98 species). A riqueza de espécies foi numericamente dominada por membros da subclasse Caenogastropoda. As famílias com o maior número de espécies foram Ranellidae (5), Muricidae (6) and Marginellidae (7). Conus regius, Cypraecassis testiculus, Lobatus goliath, Strombus pugilis, Tonna galea, Turbinella laevigata e Vasum cassiforme são macroespécies extremamente vulneráveis na região devido a sua importância comercial. A composição malacofaunística da área estudada foi comparada com a do Arquipélago de Abrolhos. ACE e CHAO 1 estimaram 133 espécies de moluscos para a região. Apesar do rápido levantamento, o número de espécies descobertas na área em questão se aproximou em 73.6% do número total estimado. O considerável número de espécies de moluscos encontradas em uma área relativamente pequena com insuficiente esforço amostral ressalta a importância dos ecossistemas recifais do Morro de São Paulo como uma área prioritária para conservação na costa do estado da Bahia, Brasil, na qual a riqueza de outros grupos de invertebrados é virtualmente desconhecida.

Lepidochitona pseudoliozonis, una nueva especie de quitón (Polyplacophora: Ischnochitonidae) del norte del Caribe / Lepidochitona pseudoliozonis, a new species of chiton (Polyplacophora: Ischnochitonidae) from the North of the Caribbean

The genus Lepidochitona (Gray 1821) contains relatively small chitons with a distinctive girdle, dorsally clothed with non-overlapping calcareous corpuscles. In the Caribbean, it is represented by four species: L. liozonis (Dall, & Simpson, 1901), L. rosea Kaas, 1972, L. rufoi García-Ríos, 2010 and L. bullocki García-Ríos, 2011. A rutinary morphological inspection of 10 specimens of a Lepidochitona species from the Florida Keys was concordant with L. liozonis (the only species of the genus informed for Florida). They did not show many morphological differences that could justify its separation from the specimens from Puerto Rico (the type locality). However, the comparison of sequences of the mitochondrial gene coding for cytochrome oxidase I (COI) of L. liozonis from Puerto Rico and the Florida specimens showed a divergence of 14%. This divergence is incompatible with a reproductively connected species. In addition to their genetic differences, the new species differs from L. liozonis in having bigger size, longer marginal spicules and a postmucronal slope very concave. Rev. Biol. Trop. 63 (2): 369-384. Epub 2015 June 01.

El género Lepidochitona (Gray, 1821) agrupa a quitones relativamente pequeños con un cinturón distintivo, por estar cubierto dorsalmente por corpúsculos calcáreos no solapados. Esta representado en el Caribe por cuatro especies: L. liozonis (Dall, & Simpson, 1901), L. rosea Kaas, 1972, L. rufoi García-Ríos, 2010 y L. bullocki García-Ríos, 2011. La inspección de una muestra de ejemplares de los cayos de la Florida permite distinguir ejemplares de lepidoquitones que podrían clasificarse como L. liozonis (la única especie del género informada para la Florida) por no presentar grandes diferencias morfológicas que justifiquen su separación de los de Puerto Rico (localidad del tipo). Sin embargo, la comparación de secuencias del gen mitocondrial que codifica para el citocromo oxidasa I (COI) de los ejemplares de la Florida con ejemplares de L. liozonis de Puerto Rico evidencia una divergencia de 14%. Esta divergencia es incompatible con especies reproductivamente conectadas. Además de sus diferencias genéticas, la nueva especie se puede distinguir de su especie gemela por ser de mayor tamaño, tener espículas marginales más largas y una pendiente posmucronal muy cóncava.

Lepidochitona bullocki, una nueva especie de quitón (Polyplacophora: Ischnochitonidae) del Caribe colombiano

Lepidochitona bullocki, a new species of chiton (Polyplacophora: Ischnochitonidae) from the Colombian Caribbean. The genus Lepidochitona is one of the most diverse in the Southern Caribbean. In order to describe this new species, twenty specimens of L. bullocki sp. nov. were collected by hand on the rocky coast, from 0.25 to 1.5m depth, and a shore distance of 1 to 5m, between the Northern section of Rodadero beach and Puerto Luz, in Santa Marta, Colombia. The specimens were small, with maximum observed size of 7.3mm. This is the fourth species of the genus Lepidochitona described for the Caribbean. The previously known species were L. liozonis (Dall & Simpson 1901), L. rosea (Kaas 1972) and L. rufoi (García-Ríos 2010). L. bullocki differs from L. liozonis and L. rosea in having a rough tegmentum and color. It differs from L. rufoi in having longer and numerous hyaline spicules, bigger size and broader central radula tooth. Lepidochitona bullocki is the only Caribbean species of the genus frequently located on the illuminated side of rocks in the shallow sublitoral zone. Rev. Biol. Trop. 59 (3): 1105-1114. Epub 2011 September 01.

El género Lepidochitona (Gray 1821) se encuentra representado en el Caribe por tres especies: L. liozonis (Dall & Simpson 1901), L. rosea (Kaas 1972) y L. rufoi. Veinte ejemplares de L. bullocki sp. nov. Fueron recolectados en un recorrido a lo largo del litoral rocoso, entre el norte de la playa del Rodadero y Puerto Luz, en Santa Marta, Colombia. Los ejemplares son pequeños, hasta 7.3mm, fueron recolectados a mano, entre 0.25 y 1.5m de profundidad, a distancias entre 1 y 5m de la orilla. Esta es la cuarta especie del género que se describe para el Caribe. Las tres especies previamente descritas son L. liozonis (Dall & Simpson, 1901), L. rosea Kaas, 1972 y L. rufoi García-Ríos, 2010. L. bullocki se diferencia de L. liozonis y L. rosea por tener la superficie del tegumento irregular y de otros colores. La misma se distingue de L. rufoi por tener muchas espículas hialinas largas, mayor tamaño, dientes centrales de la rádula anchos. Es la única especie del género en el Caribe que se localiza con mayor frecuencia en la superficie iluminada de las rocas, en el sublitoral somero.

Diversidad y microestructura de quitones (Mollusca: Polyplacophora) del Caribe de Costa Rica

Diversity and microstructure of quitons (Mollusca: Polyplacophora) from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Limón revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845); Ischnoplax pectinata (Sowerby 1840); Stenoplax boogii (Haddon 1886); S. purpurascens (C.B. Adams 1845); Acanthopleura granulate (Gmelin 1791); Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893). This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889). Rev. Biol. Trop. 59 (1): 129-136. Epub 2011 March 01.

Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845); Ischnoplax pectinata (Sowerby 1840); Stenoplax boogii (Haddon, 1886); S. purpurascens (C.B. Adams, 1845); Acanthopleura granulata (Gmelin, 1791); Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893). Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889).

Nueva especie del quitón Lepidochitona (Polyplacophora: Ischnochitonidae) de Puerto Rico

A new species of the chiton Lepidochitona (Polyplacophora: Ischnochitonidae) from Puerto Rico. The genus Lepidochitona Gray, 1821 has two species in the Caribbean: L. liozonis (Dall & Simpson, 1901) and L. rosea Kaas, 1972. We describe a third species: Lepidochitona rufoi sp. nov. from Puerto Rico. Lepidochitona rufoi differs from both in having a finely granulose tegmentum, smaller size, a very fine central radula tooth, and different anal plate form and color pattern. It also differs from L. liozonis in having longer marginal spicules. Rev. Biol. Trop. 58 (2): 635-644. Epub 2010 June 02.

El género Lepidochitona Gray, 1821 tiene dos especies en el Caribe: L. liozonis (Dall & Simpson, 1901) y L. rosea Kaas, 1972. Se describe una tercera especie: Lepidochitona rufoi sp. nov. de Puerto Rico. Lepidochitona rufoi difiere de ambas por tener un tegumento finamente granuloso, menor tamaño, una rádula con dientes centrales muy finos, la forma de la valva anal y el color diferentes. También difiere de L. liozonis por tener espículas marginales más largas.

Comunidades de quitones (Mollusca: Polyplacophora) de la Bahia de La Paz, Baja California Sur, Mexico / Polyplacophoran communities (Mollusca: Polyplacophora) at Bahia de La Paz, Baja California Sur, México

Eight species of polyplacophorans have been reported from La Bahia de la Paz, Baja California Sur, Mexico. We add Lepidochitona beanii, Chaetopleura lurida, Stenoplax limaciformis, S. mariposa, Lepidozona clathrata, L. serrata and Acanthochitona arragonites, increasing the known number of species to 15. Ordination analysis of five chiton communities at the site suggests a correlation of wave exposure to species composition and diversity: communities with intermediate wave exposure have more species (richness) and higher diversity (Shannon's index).

Quitones (Mollusca: Polyplacophora) de El Salvador, América Central / Chitons (Mollusca: Polyplacophora) from El Salvador, Central America

Collections of 11 species of shallow water Polyplacophora from El Salvador were made in July 2002. Previously only five species had been documented in El Salvador: Chaetopleura lurida (Sowerby, 1832); Ischnochiton guatemalensis (Thiele, 1910); Ceratozona angusta (Thiele, 1909); Chiton stokesii (Broderip, 1832) and Acantochitona exquisita (Pilsbry, 1893). Of these, L. guatemalensis and A. exquisita were not collected in this census. Seven other species are reported here for El Salvador for the first time: Lepidochitona beanii (Carpenter, 1857); Ischnochiton dispar (Sowerby, 1832); Stenoplax limaciformis (Sowerby, 1832); Callistochiton expressus (Carpenter, 1865); Acanthochitona arragonites (Carpenter, 1867); A. ferreirai (Lyons, 1988) and A. hirudiniformis (Sowerby, 1832). The known geographic distribution of 1. dispar is extended to the north. An un-named species of Lepidochitona is briefly described.

Callistochiton edwini n. sp. Polyplacophora: Callistoplacidae Pilsbry, 1893, do estado de Pernambuco, Brasil / Callistochiton edwini n. sp. Polyplacophora: Callistoplacidae Pilsbry, 1893 from Pernambuco state, Brazil

Callistochiton edwini n. sp. (Callistoplacidae Pilsbry, 1893) a new species from the continental platform of Pernambuco, Brazil, South America is described and illustrated. Identification may be made by characteristic morphological aspect of shell and elements of girdle, which are peculiar to this species.