Uncommon mechanism of egg incubation in the endemic Southern hermit crab Loxopagurus loxochelis: how is this phenomenon related to egg production?

Abstract

Torati, L. S. and Mantelatto, F.L. 2008. Uncommon mechanism of egg incubation in the endemic Southern hermit crab Loxopagurus loxochelis : how is this phenomenon related to egg production? -Acta Zoologica (Stockholm) 89 : 79-85The aim of the present work was to characterize the egg production of Loxopagurus loxochelis . A total of 71 ovigerous females were obtained, 28% of which were simultaneously incubating eggs at different developmental stages. This phenomenon can be the result of incomplete fertilization, or may represent a rapid gonadal cycle by this species in this area, which is, to our understanding, the best explanation of this phenomenon. Egg volume decreased 25.6% during the incubation period. The reproductive output based on dry and wet weight was 6.8 and 19.3%, respectively. Water was the prevailing component of the eggs, representing 86.0% of the total weight at initial stage, increasing to 95.1% at the final stage. Ash content increased at the same time as a decrease in the organic content occurred, indicating the consumption of yolk and absorption of salts from the water medium. In conclusion, we hypothesized that this population has the capacity to copulate and deposit another brood even before the release of the larvae from the previous one, intensifying the reproductive effort of these hermit crabs as a strategy of adaptation in a region considered the northern limit of the geographical distribution of this species.

Shell occupation by the South Atlantic endemic hermit crab Loxopagurus loxochelis (Moreira, 1901) (Anomura: Diogenidae)

“…Other studies related a trend of L. loxochelis ovigerous females on shell occupation of the gastropod B. cochlidium (Martinelli and Mantelatto, 1999;Torati and Mantelatto, 2008;Ayres-Peres et al, 2012). In the present study, L. loxochelis ovigerous females followed this pattern, occupying shells with greater volume and aperture width (B. cochlidium and S. hameastoma, respectively).…”

Reproductive variability of the Amazon River prawn, Macrobrachium amazonicum (Caridea, Palaemonidae): influence of life cycle on egg production

“…Several studies have analyzed wet weight as a proxy for the reproductive output of a species (Clarke, 1985;Galeotti et al, 2006). Other studies have used both dry weight and wet weight to estimate this parameter (Pinheiro & Terceiro, 2000;Miranda et al, 2006;Torati & Mantelatto, 2008). However, according to the results described here, we suggest the use of dry weight to provide a more accurate estimate of the amount of energy invested in reproduction, since weight or volume of the egg mass may be influenced by the amount of water in the eggs, which is quite variable between different populations of the same species.…”

“…For the fecundity analysis, only the females with embryos at the initial stage were selected to avoid brood egg loss during incubation (Torati & Mantelatto, 2008) (N = 20 individuals from each population).…”

Maternal investment in egg production: environmental and population-specific effects on offspring performance in the snapping shrimp Alpheus nuttingi (Schmitt, 1924) (Decapoda, Alpheidae)

“…For example, diff erent strategies are adopted by anomuran (Miranda et al, 2006 ;Torati and Mantelatto, 2008 ;Terossi et al, 2010) and caridean (Corey and Reid, 1991 ;Pavanelli et al, 2008 ) populations of the same species in different localities, as well as by diff erent species inhabiting the same area.…”