Diversity and Distribution of Mid- to Late-Stage Phyllosomata of Spiny and Slipper Lobsters (Decapoda: Achelata) in the Mexican Caribbean

Achelata (Palinuridae and Scyllaridae) have a flat, transparent, long-lived planktonic larva called phyllosoma, which comprises multiple stages and has a duration from a few weeks (some scyllarids) to >20 months (some palinurids). The larval development of many Achelata occurs in oceanic waters, where conventional plankton nets usually collect the early- to mid-stages but not the later stages, which remain poorly known. We examined the diversity and distribution of mid- and late-stage phyllosomata in the oceanic waters of the Mexican Caribbean, where the swift Yucatan Current is the dominant feature. The plankton samples were collected at night with a large mid-water trawl in autumn 2012 (55 stations) and spring 2013 (34 stations). In total, we obtained 2599 mid- and late-stage phyllosomata (1742 in autumn, 857 in spring) of five palinurids (Panulirus argus, Panulirus guttatus, Panulirus laevicauda, Palinurellus gundlachi, Justitia longimana) and three scyllarids (Parribacus antarcticus, Scyllarides aequinoctialis, Scyllarus chacei). Overall, the mid-stages were ~2.5 times as abundant as the late stages. The palinurids far outnumbered the scyllarids, and P. argus dominated over all the other species, followed at a distance by P. guttatus. The densities of all the species were generally low, with no clear spatial pattern, and the phyllosomata assemblage composition greatly overlapped between seasons. These results suggest the extensive mixing of the organisms entrained in the strong Yucatan Current, which clearly favors the advection of the phyllosomata in this region despite the presence of some local sub-mesoscale features that may favor short-term retention.

Development in culture of larval spotted spiny lobster Panulirus guttatus (Latreille, 1804) (Decapoda: Achelata: Palinuridae)

There is little information on the early life history of the spotted spiny lobster Panulirus guttatus (Latreille, 1804), an obligate reef resident, despite its growing importance as a fishery resource in the Caribbean and as a significant predator. We cultured newly-hatched P. guttatus larvae (phyllosomata) in the laboratory for the first time, and the growth, survival, and morphological descriptions are reported through 324 days after hatch (DAH). Phyllosomata were cultured at 25 °C in a flow-through seawater system within a series of custom 80 l plankton-kreisel tanks and provided with ongrown Artemia and mussel gonad. Mean body length (BL) of phyllosomata was 1.70 mm (N = 10) at hatch and increased linearly to 22.20 mm at 226 DAH (N = 3). Morphological characters from a total of 164 sampled phyllosomata were ascribed to nine distinct developmental stages (stages I-IX), and described and illustrated. Although no final stage phyllosomata (stage X) were obtained, the BL in the final stage was extrapolated at 39.6 mm using a Gompertz function, expressing the relationship between phyllosoma stages and BL. The total duration of phyllosomata for P. guttatus was estimated at 410 d, with the 5th and 95th percentiles at 334 and 526 d, respectively. Our data suggest that P. guttatus has a larger body size in the final larval stage and a substantial pelagic larval duration compared with other related panulirid lobsters in its geographic range. The described morphological and biological attributes associated with the early-life history for this species can inform future studies, and add value to models of distribution and population connectivity.

Isolation and characterization of eight polymorphic microsatellites for the spotted spiny lobster,Panulirus guttatus

Microsatellite sequences were isolated from enriched genomic libraries of the spotted spiny lobster,Panulirus guttatususing 454 pyrosequencing. Twenty-nine previously developed polymerase chain reaction primer pairs ofPanulirus argusmicrosatellite loci were also tested for cross-species amplification inPanulirus guttatus.In total, eight consistently amplifying, and polymorphic loci were characterized for 57 individuals collected in the Florida Keys and Bermuda. The number of alleles per locus ranged from 8 to 20 and observed heterozygosities ranged from 0.409 to 0.958. Significant deviations from Hardy–Weinberg equilibrium were found in one locus from Florida and three loci from Bermuda. Quality control testing indicated that all loci were easy to score, highly polymorphic and showed no evidence of linkage disequilibrium. Null alleles were detected in three loci with moderate frequencies ranging from (20% to 22%). These eight microsatellites provide novel molecular markers for future conservation genetics research ofP. guttatus.

Aggressive behaviour of spotted spiny lobsters (Panulirus guttatus) in different social contexts: the influence of sex, size, and missing limbs

Panulirus guttatus is a sedentary spiny lobster that exhibits cryptic behaviour and a low degree of gregariousness. Because these lobsters are obligate coral reef-dwellers and avoid sandy expanses, they are potentially distributed in relatively small, discrete populations with variable social contexts, which can strongly influence the expression of aggression. The present study examined the relative importance of sex, size, and the number of missing limbs in the shelter-related aggressive behaviour of replicated groups of four lobsters that differed in social context (i.e. same-sex and mixed-sex groups). Each group was held in a seawater tank with a single artificial cave-like shelter. The interior of the cave was video-recorded for 72 h and the number of aggressions performed by each individual was quantified in a 10-min segment of video per hour. Most aggressions were related to occupancy of the shelter inner space and tended to end when individuals were sufficiently spaced out. In general, per-capita rates of aggression were higher at night and size was an important predictor of aggressiveness among individuals of the same sex. Males were substantially more aggressive than females, but the number of missing limbs significantly impacted the degree of aggressiveness in males. In mixed-sex groups, fewer aggressions occurred when the largest individual was a male than when it was a female, suggesting that it may take longer for smaller males to assert themselves. Our results provide insights into some potential consequences of increase in fishing pressure and loss of habitat complexity in Caribbean reefs for the social behaviour and population dynamics of these lobsters.