Phylogenetic Relationships Among Japanese Species of the Genus Ischnochiton (Polyplacophora: Ischnochitonidae), Including a New Species.

Seven (including one new) species of the polyplacophoran genus Ischnochiton (Ischnochitonidae) from the Pacific coast of Japan, namely, I. boninensis, I. comptus, I. manazuruensis, I. hakodadensis, I. hayamii sp. nov., I. paululus, and I. poppei, were investigated on the basis of DNA sequence analyses of COI, 16S rRNA, 18S rRNA, and 28S rRNA gene regions. For the latter four species, SEM observations were simultaneously carried out. A molecular phylogenetic tree based on the four gene regions for 18 chiton species indicated that the seven Japanese Ischnochiton species are polyphyletic and originated from two different clades. A haplotype network based on the COI gene region for the six Japanese Ischnochiton species, except I. hakodadensis, showed that the genetic distances among them were large. The SEM observations revealed that the denticles of the major lateral teeth in the seven Japanese Ischnochiton species were bicuspid, and an accessory process was only observed in the minor lateral teeth of I. hakodadensis. Ischnochiton hayamii sp. nov. cooccurs with I. boninensis, I. comptus, and I. manazuruensis at the two investigated localities, and was difficult to distinguish from other, similar species by naked eyes. However, these can be discriminated based on a combination of adult body size, girdle scales, and valve sculpturing in the lateral and central areas.

[Lepidochitona bullocki, a new species of chiton (Polyplacophora: Ischnochitonidae) from the Colombian Caribbean]. / Lepidochitona bullocki, una nueva especie de quitón (Polyplacophora: Ischnochitonidae) del Caribe colombiano.

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 (Garcia-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.

Composition of the genus Loricella (Mollusca: Polyplacophora: Loricidae) and the description of two new species.

The genus chiton Loricella is revised. It comprises nine species. Two of these species, L. neoguinensis n. sp. and L. solomonensis n. sp., are described as new. Based on the analysis of morphological features studied using a scanning electron microscope, a revised diagnosis of the genus is provided. The characters diagnostic for this that distinguish it from the related genus Squamophora are as follows: a tubular hollow inside the dorsal scales, bristles on the dorsal side of the girdle, a wide ventral mouth region, a narrow mantle fold covered with simple longitudinally ribbed scales, smooth ventral scales, pits arranged in longitudinal rows in the central area of the tegmentum, and a bicuspid head of the major lateral teeth of the radula.

Composition of the genus emConnexochiton/em Kaas, 1979 (Mollusca: Polyplacophora: Ischnochitonidae).

The species composition of the genus Connexochiton is revised. So far, six Recent species of the genus Connexochiton have been known: C. platynomenus, C. kaasi, C. crassus, C. bromleyi, C. moreirai and C. discernibilis After the present revision, the genus consists of Connexochiton platynomenus, C. kaasi, C. crassus, as well as three new species, C. costatus n. sp. from the Philippines, C. kermadeci n. sp. from New Zealand and C. solomonicus n. sp. from the Solomon Islands. Connexochiton discernibilis was assigned to the ischnochitonid genus Stenosemus (now Stenosemus discernibilis). Connexochiton bromleyi and C. moreirai are transferred back to the genus Ischnochiton. Principle features of the genus Connexochiton include: a distinctive shape of the valves with the hind edge of the intermediate valves noticeably turned down, which makes the lateral areas narrow and appearing strongly raised; tegmentum delicately sculptured by quincuncially arranged triangular granules that form an alveolate pattern; each granule has 9 to 11 aesthete pores; apophyses are connected medially by a short jugal plate, dorsal scales of the girdle are strongly bent, with short longitudinal ribs or spherules or both; head of the major lateral teeth of radula is unicuspid and sickle-shaped. An identification key for the species of the genus Connexochiton is provided.

[A new species of the chiton Lepidochitona (Polyplacophora: Ischnochitonidae) from Puerto Rico]. / Nueva especie del quitón Lepidochitona (Polyplacophora: Ischnochitonidae) de 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.

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.

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.