Ovigerous females of the porcellanid crab Petrolisthes laevigatus were collected at monthly intervals in the rocky intertidal of Playa Rosada, south-central Chile between October 1993 and February 1994. Egg production and chemical composition of eggs during the incubation period were studied. Females produced between 56 and 1141 eggs; female carapace length and width ranged from 8.51 mm to 18.24 mm and 8.36 mm to 19.46 mm, respectively. A linear regression between egg number/volume of egg mass and the area of the abdomen best described the egg production in this species. Egg volume increased from 0.226 mm3 (freshly-laid eggs) to 0.380 mm3 (near to hatching), which represents a 40.5% volume increase. During the incubation period P. laevigatus females suffered a mean brood loss of 17.7%. Water content increased steadily during embryogenesis, representing 60.7% and 77.6% of the wet weight of newly-produced and advanced eggs, respectively. Dry weight and organic matter decreased during incubation, while ash content increased. Compared to data from other decapods, in P. laevigatus egg content of organic matter is relatively low and ash content for eggs is relatively high. These differences may be related to both the special morphology of porcellanid zoeae and the thick and resistant outer egg membrane. The reproductive output (RO) in P. laevigatus, based upon wet and dry weight, was 0.074 and 0.057, respectively. In both cases, RO was almost constant throughout the different size-classes of female. Compared to caridean shrimps in polar and temperate regions, P. laevigatus has a low weight-specific gonad output. Brood mass in P. laevigatus constituted an average of 7.4% of the female body wet weight. Although this value is relatively low, it is within the range (from 3% to 22%) reported for brachyuran crabs.
|Number of pages||15|
|Journal||Archive of Fishery and Marine Research|
|State||Published - 1996|