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

Abstract

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

Reproduction of Ophioplocus januarii (Echinodermata: Ophiuroidea): a continuous breeder in northern Patagonia, Argentina

“…This has been confirmed in several studies (Selva ku ma raswamy & Byrne 1995, Falkner & Byrne 2003, Grange et al 2004, Borges et al 2009). Continuous breeding has been typically related to warm-water and deepsea species, with a trend toward longer spawning periods in the lower latitudes (Hendler 1991), even though for some deep-sea species a reproductive seasonality has been reported (Tyler & Gage 1980, 1982, Gage et al 2004.…”

“…This is particularly true for the Southern Hemisphere, where reproductive studies have been conducted for only a few species (Selvakumaraswamy & Byrne 1995, Stewart & Mladenov 1995, Falkner & Byrne 2003, Grange et al 2004, Byrne et al 2008, Borges et al 2009). The present study documents the reproductive biology of Ophioplocus januarii (Lütken, 1856) from the temperate waters of northern Patagonia, Argentina, through histological examination of the gonads and by the gonad index method.…”

Brooding behavior in the shallow‐water brittle star Ophioderma wahlbergii

“…Normally, hermaphrodites comprise <1% of the population of gonochoric ophiuroids (Hendler ; Hendler & Tran ; Borges et al. ). The presence of brooded young revealed that hermaphrodites of O. wahlbergii can be fertile, but none of them brooded substantial numbers of young.…”

“…In contrast, all species of the genus Ophioderma are large and gonochoric, meaning that they have separate sexes (Hendler ; Borges et al. ).…”

Reproductive biology of Ophiocoma aethiops and O. alexandri (Echinodermata: Ophiuroidea) from Estacahuite Bay, Oaxaca, Mexico

“…frequency, size and features of gametes, presence/absence of phagocytes, as well as thickness and presence/absence of a gonadal wall of fibrous networks) with the GDS used for other ophiuroid species (Cuénot 1888, Selvakumaraswamy & Byrne 1995, Stewart & Mladenov 1995, Falkner & Byrne 2003, Tominaga et al 2004, Borges et al 2009). For both sexes 4 stages were designated: gametogenesis, mature, spawning and post-spawning.…”