Ophiomusium acuferum (Ophiolepididae) and Ophiomisidium pulchellum (Ophiuridae) (Ophiuroidea: Echinodermata), redescription based on the Brazilian specimens

Ophiomusium (Ophiolepididae) and Ophiomisidium (Ophiuridae) are similar, but differ in features such as size of the adult, number of disc dorsal plates, length of the arms, shape of the first ventral arm plates and number of the tentacle. In this contribution, a large number of specimens of Ophiomusium acuferum Lyman, 1869 and Ophiomisidium pulchellum (Wyville Thomson, 1878) were sampled from southeastern and southern Brazilian at depths ranging from 46 to 1300 m. A close analysis has shown that specimens identified as Ophiomisidium pulchellum (C.W. Thomson, 1877) in several Brazilian museums are actually Ophiomusium acuferum Lyman, 1875. A total of 2330 individuals were examined: 2046 specimens of Ophiomusium acuferum ('Evaluation of the sustainable potential of living resources from the Brazilian Economic Exclusive Zone/Score South - Benthos' - REVIZEE; 'Rational usage of coastal ecosystems from the Brazilian Tropical Region: São Paulo State - Integrated Project/Subproject Benthos' - INTEGRADO; and the MD55/Brazil) and 284 of Ophiomisidium pulchellum (MD55/Brazil). The disc diameter of each individual was measured and the specimens were digitally photographed. The samples studied are deposited in the Museum of Zoology of the University of Campinas and Institute of Biology at the Federal University of Rio de Janeiro. The specimens from the MD55 are deposited at the Paris Museum National d'Histoire Naturelle. An identification key to these species is provided here. A detailed morphological analysis and redescription of both species, comparisons, and their geographic distribution in Brazil are discussed.

Ophiomusium acuferum (Ophiolepididae) and Ophiomisidium pulchellum (Ophiuridae) (Ophiuroidea: Echinodermata), redescription based on the Brazilian specimens

Ophiomusium (Ophiolepididae) and Ophiomisidium (Ophiuridae) are similar, but differ in features such as size of the adult, number of disc dorsal plates, length of the arms, shape of the first ventral arm plates and number of the tentacle. In this contribution, a large number of specimens of Ophiomusium acuferum Lyman, 1869 and Ophiomisidium pulchellum (Wyville Thomson, 1878) were sampled from southeastern and southern Brazilian at depths ranging from 46 to 1300 m. A close analysis has shown that specimens identified as Ophiomisidium pulchellum (C.W. Thomson, 1877) in several Brazilian museums are actually Ophiomusium acuferum Lyman, 1875. A total of 2330 individuals were examined: 2046 specimens of Ophiomusium acuferum ('Evaluation of the sustainable potential of living resources from the Brazilian Economic Exclusive Zone/Score South - Benthos' - REVIZEE; 'Rational usage of coastal ecosystems from the Brazilian Tropical Region: São Paulo State - Integrated Project/Subproject Benthos' - INTEGRADO; and the MD55/Brazil) and 284 of Ophiomisidium pulchellum (MD55/Brazil). The disc diameter of each individual was measured and the specimens were digitally photographed. The samples studied are deposited in the Museum of Zoology of the University of Campinas and Institute of Biology at the Federal University of Rio de Janeiro. The specimens from the MD55 are deposited at the Paris Museum National d'Histoire Naturelle. An identification key to these species is provided here. A detailed morphological analysis and redescription of both species, comparisons, and their geographic distribution in Brazil are discussed.

Ophiomusium acuferum (Ophiolepididae) and Ophiomisidium pulchellum (Ophiuridae) (Ophiuroidea: Echinodermata), redescription based on the Brazilian specimens

Ophiomusium (Ophiolepididae) and Ophiomisidium (Ophiuridae) are similar, but differ in features such as size of the adult, number of disc dorsal plates, length of the arms, shape of the first ventral arm plates and number of the tentacle. In this contribution, a large number of specimens of Ophiomusium acuferum Lyman, 1869 and Ophiomisidium pulchellum (Wyville Thomson, 1878) were sampled from southeastern and southern Brazilian at depths ranging from 46 to 1300 m. A close analysis has shown that specimens identified as Ophiomisidium pulchellum (C.W. Thomson, 1877) in several Brazilian museums are actually Ophiomusium acuferum Lyman, 1875. A total of 2330 individuals were examined: 2046 specimens of Ophiomusium acuferum ('Evaluation of the sustainable potential of living resources from the Brazilian Economic Exclusive Zone/Score South - Benthos' - REVIZEE; 'Rational usage of coastal ecosystems from the Brazilian Tropical Region: São Paulo State - Integrated Project/Subproject Benthos' - INTEGRADO; and the MD55/Brazil) and 284 of Ophiomisidium pulchellum (MD55/Brazil). The disc diameter of each individual was measured and the specimens were digitally photographed. The samples studied are deposited in the Museum of Zoology of the University of Campinas and Institute of Biology at the Federal University of Rio de Janeiro. The specimens from the MD55 are deposited at the Paris Museum National d'Histoire Naturelle. An identification key to these species is provided here. A detailed morphological analysis and redescription of both species, comparisons, and their geographic distribution in Brazil are discussed.

Gametogenic cycle of Ophioderma januarii, a common Ophiodermatidae (Echinodermata: Ophiuroidea) in southeastern Brazil

This study describes the gametogenic cycle of Ophioderma januarii Lütken, 1856, a common species of ophiuroid in Southeastern Brazil. The specimens were collected during the project "Biodiversidade Bêntica Marinha no Estado de São Paulo-BIOTA/FAPESP-Bentos Marinho" (Marine benthic biodiversity in the State of São Paulo-BIOTA/ Fapesp-Marine Benthos) which was conducted off the northern coast of the state of São Paulo. Specimens were captured monthly between February 2001 and December 2002. Due to the low number of individuals the monthly data was grouped in seasons (spring to winter). A total of 101 specimens were obtained: 33 in spring, 10 in summer, 23 in autumn, and 35 in winter. The gonads of eighty-eight individuals (45 females, 42 males, and one hermaphrodite) were analyzed histologically. The male and female gametogenic cycles were classified into five different gonadal stages, which were analyzed separately. The reproductive pattern could be defined through histological analyses of male and female gonads, together with oocyte diameter frequency. Some general conclusions could also be reached: this is a gonochoric species that reproduces year-round but increases its gonadal activity during summer; based on the size of its mature oocytes, it has lecithotrophic development. Apparently, its recruitment is enhanced in late summer, and smaller individuals are more frequent during autumn and winter.

Gametogenic cycle of Ophioderma januarii, a common Ophiodermatidae (Echinodermata: Ophiuroidea) in southeastern Brazil

This study describes the gametogenic cycle of Ophioderma januarii Lütken, 1856, a common species of ophiuroid in Southeastern Brazil. The specimens were collected during the project "Biodiversidade Bêntica Marinha no Estado de São Paulo-BIOTA/FAPESP-Bentos Marinho" (Marine benthic biodiversity in the State of São Paulo-BIOTA/ Fapesp-Marine Benthos) which was conducted off the northern coast of the state of São Paulo. Specimens were captured monthly between February 2001 and December 2002. Due to the low number of individuals the monthly data was grouped in seasons (spring to winter). A total of 101 specimens were obtained: 33 in spring, 10 in summer, 23 in autumn, and 35 in winter. The gonads of eighty-eight individuals (45 females, 42 males, and one hermaphrodite) were analyzed histologically. The male and female gametogenic cycles were classified into five different gonadal stages, which were analyzed separately. The reproductive pattern could be defined through histological analyses of male and female gonads, together with oocyte diameter frequency. Some general conclusions could also be reached: this is a gonochoric species that reproduces year-round but increases its gonadal activity during summer; based on the size of its mature oocytes, it has lecithotrophic development. Apparently, its recruitment is enhanced in late summer, and smaller individuals are more frequent during autumn and winter.

Gametogenic cycle of Ophioderma januarii, a common Ophiodermatidae (Echinodermata: Ophiuroidea) in southeastern Brazil

This study describes the gametogenic cycle of Ophioderma januarii Lütken, 1856, a common species of ophiuroid in Southeastern Brazil. The specimens were collected during the project "Biodiversidade Bêntica Marinha no Estado de São Paulo-BIOTA/FAPESP-Bentos Marinho" (Marine benthic biodiversity in the State of São Paulo-BIOTA/ Fapesp-Marine Benthos) which was conducted off the northern coast of the state of São Paulo. Specimens were captured monthly between February 2001 and December 2002. Due to the low number of individuals the monthly data was grouped in seasons (spring to winter). A total of 101 specimens were obtained: 33 in spring, 10 in summer, 23 in autumn, and 35 in winter. The gonads of eighty-eight individuals (45 females, 42 males, and one hermaphrodite) were analyzed histologically. The male and female gametogenic cycles were classified into five different gonadal stages, which were analyzed separately. The reproductive pattern could be defined through histological analyses of male and female gonads, together with oocyte diameter frequency. Some general conclusions could also be reached: this is a gonochoric species that reproduces year-round but increases its gonadal activity during summer; based on the size of its mature oocytes, it has lecithotrophic development. Apparently, its recruitment is enhanced in late summer, and smaller individuals are more frequent during autumn and winter.