Larval development of the sub-Antarctic hermit crab Pagurus comptus reared in the laboratory

GUSTAVO ALEJANDRO LOVRICH; SVEN THATJE,

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Año: 2006 vol. 86 p. 743 - 749

0025-3154

Fecundity, hatching rhythm, and the planktotrophic larval development of the hermit crab Paguruscomptus from sub-Antarctic waters of the Beagle Channel (Tierra del Fuego) were studied under controlledlaboratory conditions of temperature, light cycle, food supply, and salinity. Fecundity was low, rangingfrom 134 to 848 eggs per female (cephalotoraxic shield length, SL, 2.3^5.0mm). Hatching observed in thelaboratory ranged from 6 to 30 d. The larval development was studied in laboratory cultures fed withArtemia sp. nauplii and kept at constant 7.0
0.58C. Larvae invariably passed through four zoeal instarsand one megalopa stage. Mean durations of the zoeal stages I to IV were 14.3
1.8, 16.7
4.6, 23.2
6.5,33.4
9.2 d, respectively. Combined with the 43.8
5.6 d recorded for the survived megalopae, we suggestthat the complete larval development lasts about four months. Starved larvae, on average, survived for22
8.1d (maximum 38 d) by far exceeding the zoea I duration in fed larvae, but did not reach themoult to the zoea II stage. Unlike other sub-Antarctic decapods, which show a tendency towards abbreviatedor endotrophic larval developments at high latitudes, hermit crabs, at their southernmostdistributional limit on Earth, show an extended and fully planktotrophic larval development and thusneed to synchronize larval release with short periods of high primary production.