Reproductive bionomics of some shallow-water lysianassoids in the Saint Lawrence Estuary, with a review on the fecundity of the Lysianassoidea (Crustacea, Amphipoda)

Abstract

The life history and fecundity of five shallow-water lysianassoids from the Saint Lawrence Estuary were examined. Orchomenella minuta and Or. pinguis are annual and iteroparous (two broods), Psammonyx terranovae is iteroparous (two broods) and probably biennial, and Anonyx sarsi and Onisimus litoralis are biennial and semelparous. Females of A. sarsi and On. litoralis cease feeding on bait shortly before or after oviposition, whereas females of the iteroparous Or. pinguis stop feeding on bait only when broods are in the latest stages of embryo development. These ontogenetic changes may result from gut constriction caused by developing ovaries and broods, or may be due to behavioural changes. Data on the fecundity of the Lysianassoidea are reviewed, and it is concluded that deep-living species are probably much less fecund than shallow-living species. Anonyx nugax, Or. pinguis, and A. sarsi are more fecund than other lysianassoids, possibly because of their high-risk carrion-feeding and suprabenthic foraging activities.

Local anthropogenic contamination affects the fecundity and reproductive success of an Arctic amphipod

“…Occasionally the gravid females were found with full ovaries with unfertilized oocytes as well, confirming that Orchomenella pinguis is iteroparous as suggested by Sainte-Marie (1990). While the size of the gravid females corresponded to the size of gravid females collected in Saint Lawrence Estuary (Sainte-Marie 1990), the broods were found to be much smaller in the present study.…”

Annual routines and life history of the amphipod Onisimus litoralis: seasonal growth, body composition and energy budget

“…In this study, we identify a 2 yr semelparous life cycle of Onisimus litoralis, well in accordance with earlier studies in the Beaufort Sea (Boudrias & Carey 1988), in the Saint Lawrence Estuary (Sainte-Marie et al 1990) and on Svalbard (Węs8awski et al 2000, Węs8awski & Legeż y?ska 2002. However, our study does not provide any evidence for iteroparity as suggested by Węs8awski et al (2000).…”

Life history of Onisimus caricus (Amphipoda: Lysianassoidea) in a high Arctic fjord

“…Only Alicella gigantea and Eurythenes gryllus have been reported to have larger eggs (Sainte-Marie et al 1990), but these are species of a considerably larger size. The brood size is small, but of comparable size to many other lysianassoids (Sainte-Marie et al 1990). However, the lysianassoid species in the genus Anonyx, which are also very common in Adventfjorden, seem to have a different strategy when it comes to reproduction.…”

“…Sampling with baited traps probably affects the estimates of relative abundance of the different cohorts. The smallest juveniles and ovigerous females are most likely underrepresented, due to different food preferences and a retraction of the gut in ovigerous females (Sainte-Marie et al 1990, Legeżyńska 2008; and males are overrepresented during the mating season (Conlan 1991). Nevertheless, it is possible to detect the different cohorts and thereby to study the life cycle of the species.…”

“…Among these are also Arctic amphipods (Boudrias & Carey 1988, Sainte-Marie et al 1990, Poltermann et al 2000, Węs8awski et al 2000, Beuchel & Lønne 2002, Węs8awski & Legeżyńska 2002, Arndt & Beuchel 2006. In general, Arctic amphipods have a single brood per year, which is released in synchrony with optimal conditions, resulting in distinct cohorts, which can be used for life cycle analyses.…”