title: Sexual Reproductive Biology of a Colonial RotiferSinantherina socialis(Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?
abstract: In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotiferSinantherina socialis,and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found inS. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation inS. socialisis the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips.
authors.affiliation: Universidad Autónoma de Aguascalientes. Centro Básico. Departamento de Química. Avenida Universidad 940, Aguascalientes, Ags. C.P. 20100, México.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rico-Martínez
authors.affiliation: University of Texas at El Paso. Department of Biological Sciences. 500 West University Avenue. El Paso, Texas 79968-0519, USA.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Walsh
keywords: Sinantherina socialis; behaviour; colonial rotifer; invertebrate reproduction; male morphology; mating; video analysis