|Pairing behaviour, reproduction and diet in the deep-sea holothurian genus Paroriza (Holothuroidea: Synallactidae)|
|Tyler, P.A.; Young, C.M.; Billett, D.S.M.; Giles, L.A. (1992). Pairing behaviour, reproduction and diet in the deep-sea holothurian genus Paroriza (Holothuroidea: Synallactidae). J. Mar. Biol. Ass. U.K. 72(2): 447-462|
|In: Journal of the Marine Biological Association of the United Kingdom. Cambridge University Press/Marine Biological Association of the United Kingdom: Plymouth. ISSN 0025-3154, more|
Diets; Sexual reproduction; Social behaviour; Holothuroidea [WoRMS]; Paroriza prohoi Hérouard, 1902 [WoRMS]; Marine
Deep-sea holothurians of the genus Paroriza (Family Synallactidae) have often been observed or photographed in pairs or triplets. Observations of tracks on the sea floor suggest that pairs may remain together for some time. The reasons for pairing were explored in a study of reproductive condition and diet. Both species of Paroriza studied were found to be simultaneous hermaphrodites producing yolky oocytes. Oocytes of Paroriza pallens were approximately equals 350 mu m in diameter, whereas those of P. prouhoi were up to 450 mu m. Examination of oocyte size-frequency distributions suggests that reproduction is continuous for both species. Neither mean oocyte size, nor shape of the oocyte size-frequency distribution differed significantly between paired and unpaired P. pallens collected during the same season. The authors hypothesize that pairing increases the likelihood of external fertilization and that spawning in these species may be induced at any time by the presence of a conspecific rather than by seasonal cues.