Copulatory behaviour and sexual morphology of three Fabaeformiscandona Krstić, 1972 (Candoninae, Ostracoda, Crustacea) species from Japan, including descriptions of two new species

Abstract

Copulatory behaviour and sexual morphology of three Fabaeformiscandona Krstić, 1972 (Candoninae, Ostracoda, Crustacea) species from Japan, including descriptions of two new species Robin J. Smith AE Takahiro Kamiya Ó Springer Science+Business Media B.V. 2007Abstract Two new species of Fabaeformiscandona and collections of Fabaeformiscandona japonica (Okubo, 1990. Bulletin Biogeography Society of Japan 45: 39-50) from Japan have provided an opportunity to study the copulatory behaviour and sexual morphology of these species. The male uses the large fifth limb palps to force open the female carapace for copulation. However, the female has an enlarged overlapping flap over the posterior of the carapace which appears to hinder the male from opening the carapace, thus the female retains some control over potential mates. During copulation, the males' fifth limbs, caudal ramus and m process of the hemipenes and the females' protrusion of the female reproductive organ play a crucial role in providing a secure interface between the sexual organs to allow for the transfer of the giant spermatozoa. Development of the sexual organs in both sexes begins during the A-2 instar, and the protrusion of the female genital lobe begins to form during the A-1 instar.

On some Recent non-marine ostracods from northern China, with description of one new species

“…Comparisons with the Japanese specimens.-In chaetotaxy, the Chinese speci mens are identical to those described by Smith & Kamiya (2007), except that the dorso-apical seta on the 3rd segment of A1 is not smooth but setulose. This minor difference is here considered as within-species variation.…”

“…subvomerina Liu & Lu, 1999) (Okubo, 2004). It was formally named by Smith & Kamiya (2007) who collected the specimens from an artificial pond in Japan. The species was also found in Lake Biwa (Smith & Janz, 2008).…”

“…Candona quasiakaina Karanovic & Lee, 2012 is reported for the first time outside South Korea. Fabaeformiscandona myllaina Smith & Kamiya, 2007 and Heterocypris sanukiensis Okubo, 2004 nomen nudum (as Heterocypris auricularis sp. nov. in this paper) are new for areas outside of Japan, llyocypris mongolica Martens, 1991 is reported for the first time outside of Mongolia.…”

A review of rice field ostracods (Crustacea) with a checklist of species

“…Only one known invasive species of ostracod found in rice fields, Fabaeformiscandona subacuta, reproduces sexually (Smith and Kamiya, 2007;Escrivà et al, 2012). However, this species tends to prefer permanent waterbodies, with rice fields being the only type of temporary water body it is found in (Escrivà et al, 2012).…”

How is a giant sperm ejaculated? Anatomy and function of the sperm pump, or “Zenker organ,” in Pseudocandona marchica (Crustacea, Ostracoda, Candonidae)

“…We therefore concur with Nordqvist's (1885) interpretation that a Zenker organ is free of spermatozoa unless copulation takes place. The Zenker organ has been considered as an ejaculatory apparatus from the end of the nineteenth century onward based on the following evidence: (1) this organ is part of the vas deferens and situated just behind the seminal vesicle and (2) a pulsating movement by muscles can be observed during copulation (e.g., Smith and Kamiya 2007). However, none of the authors describing the Zenker organ has explained the steps of the sperm pumping process in detail.…”