Egg Production Strategies of the Tropical Hermit Crab Paguristes Tortugae from Brazil

Abstract

A B S T R A C TThe aim of the present study was to characterize the total and seasonal fecundity of the hermit crab Paguristes tortugae as well as the influence of shell type on fecundity using the morphometric relationship. Ovigerous females were collected monthly from January to December, 1998, in the infralittoral region of Anchieta Island. Samplings were performed using SCUBA. The hermit crabs and the gastropod shells were measured. Hermit wet weight and shell dry weight were recorded. For the fecundity analysis, only ovigerous females with the eggs in the early phase of development were selected. The number of eggs carried by individuals of several sizes (shield length), condition of development, and egg size were determined. A high percentage (69.88%) of ovigerous females with eggs in the early phase of development were captured, with a low frequency (4.29%) of females with eggs in the final stage of development. Size-frequency distribution during the months showed two peaks in the ovigerous female population (2.5 to 3.4 mm and 4.0 to 5.4 mm of SL). Mean ± SD fecundity was 132 ± 102 eggs and tended to increase with increasing SL. No significant difference in fecundity occurred among the various seasons of the year. The results showed continuous and elevated reproduction of P. tortugae, with a high reproductive potential for the population. The pattern of the frequency distribution of ovigerous females tending to bimodality may be characteristic of a population with a two-year life cycle. Considering the four shells most occupied by P. tortugae (Pisania auritula, Cerithium atratum, Morula nodulosa, and Leucozonia nassa), the highest fecundity was observed for ovigerous females occupying larger shells (P. auritula and L. nassa). The reproductive aspects of P. tortugae were related to strategies developed to compensate for interspecific competition, i.e., high and continuous reproductive effort, early maturity, low fecundity, and larger eggs produced.

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

“…(2004; p. 2341) after a study on the gonadal development of L. loxochelis proposed that ‘this hermit crab species has the capacity to copulate and deposit another brood soon after the release of the larvae, thus intensifying the reproductive effort’. In the present study population, ovigerous females of different sizes were observed with embryos at all developmental stages, suggesting that embryonic development is a continuous process (Mantelatto et al . 2002), in accordance with their continuous reproductive activity (Martinelli et al .…”

“…Loxopagurus loxochelis produces more eggs than Paguristes Dana 1851 genera (Negreiros‐Fransozo et al . 1992; Garcia and Mantelatto 2001; Mantelatto et al . 2002; Williams 2002), which, for instance, produce larger eggs.…”

Characterization of epibionts associated with gastropod shells inhabited by Isocheles sawayai (Crustacea: Decapoda: Anomura) on the north coast of Santa Catarina

“…Thus, the hypothesis that best adjusts to the use of shells with less internal infestation by ovigerous females is related to the physiological need of the species to maximize reproductive success. Mantelatto et al (2002), studying Paguristes tortugae Schmitt, 1933, found a positive correlation between fecundity and the internal volume of the shell, suggesting that the larger the volume, the greater the fecundity of the female. In the present study, this might explain the low prevalence of internal epibionts in the shells occupied by ovigerous females, because internal epibionts limit the space available for oviposition and development of fertilized eggs, and some polychaete epibionts of the genus Polydora use hermit crab eggs as food (Williams, 2002).…”

Shell occupation by the hermit crab Dardanus insignis (Decapoda, Diogenidae) from the north Coast of São Paulo state, Brazil

“…According to Hazlett et al (2005) females of Clibanarius vittatus (Bosc, 1802) that occupied heavier shells -larger than their ideal size -tended not to be ovigerous, whereas ovigerous females were most commonly found in adequate shells. When analyzing egg production strategies in Paguristes tortugae (Schmitt, 1933), Mantelatto et al (2002) reported that the occupation of some shells provided an increase in fecundity. The same was shown for Loxopagurus loxochelis (Moreira, 1901) by Torati and Mantelatto (2008), who also showed that this increase in fecundity takes place particularly when the shell is lighter.…”