Artificial shelters (casitas) as habitats for juvenile spiny lobsters Panulirus argus in the Mexican Caribbean

Abstract

The cryptlc and shelter-seeklng behav~our of spiny lobsters Panulirus argus Latrellle prompted the use of artlflclal shelters to examine the juvenlle population structure at Cayos-Contoy. Quintana Roo, Mexlco We tested the hypothesis that habltat type had no influence on shelter occupancy T h e arhflcial shelters used were concrete structures w ~t h a PVC frame ( m m -s l z e casltas) Macrofauna a n d potential predators associated wlth the mm-casltas were also quantified The size of the lobsters harbored by these structures emphasized the Importance of the Cayos-Contoy as a nursery habltat for P argus Differences in mini-casita occupancy by luvendes and the assoclatlon between habltat and lobster size groups suggest that availab~llty of natural habitats had an influence on casita occupancy The penodlc removal ot all lobsters from the mini-casitas resulted in the vacancies being occupled mostly by a size-spec~flc group oi juveniles Trans~tional (16 to 25 m m carapace length, CL) and postalgal (26 to 35 mm CL) luvenile stages recruited malnly to vegetated habitats with larger lobsters occupylng patch reef habitats Mlni-caslta occupancy was dominated by transitional and post-algal early juvenlle stages (41 1 and 34 6% respectlvely) The fact that the highest percentage of minl-caslta occupancy is by transitional juvenlle P argusls considered to represent a 'population bottleneck effect