Sabater, J. University of Puerto Rico (RUM), jsabater@caribe.net
Garcia, J. University of Puerto Rico (RUM), renigar@caribe.net

 
PRELIMINARY OBSERVATIONS ON THE VERTICAL DISTRIBUTION AND DIURNAL MIGRATION OF PHYLLOSOMA LARVAE IN THE CARIBBEAN SEA
 
As part of a multidisciplinary study aimed to understand the recruitment dynamics of fish and lobster larvae in the south coast of Puerto Rico, phyllosoma larvae were sampled to describe their vertical and horizontal distribution. The objective of the study was to examine the taxonomic composition of the larvae, determine their distribution along an inshore-offshore gradient, and to describe their vertical distribution. Data regarding to vertical distribution and migration will be discussed in this poster. Lobster phyllosoma larvae were sampled during three cruises in February, August and December, 1995 and May, 1996 to examine temporal, spatial and ontogenetic distribution patterns across an inshore-offshore gradient off La Parguera. Samples were taken at six different distances across the inshore-offshore gradient (6, 10, 13, 16, 29 and 46 Km from the coastline) along three parallel transects (67 00', 67 03' and 67 06' W). In addition to the 18 standard stations, one station was sampled consecutively at four hour intervals during an entire 24 hour cycle to investigate the diel vertical migration of the larvae. Samples were collected in stratified step-oblique tows at three discrete depths (0 -20 m; 21-40 m; 41 - 60m) at the standard stations. Sampling depth at the 24 hour station varied according to oceanographic conditions, such as the depth of maximum chlorophyll concentration associated with the thermocline. A 1 m2 Tucker Trawl system fitted with three 0.202 mm mesh was employed in sampling. Larvae were identified into three genera (Panulirus, Scyllarides and Scyllarus) of which Panulirus was the most abundant (69 %) followed by Scyllarides (26 %) and Scyllarus (5 %). Due to the high temporal variability, discerning a clear distributional pattern was very difficult. Nevertheless, later stage larvae (X-XI) were more abundant at the deeper depth strata (41 - 60 m) and absent at the surface during the day. The highest abundance of larvae occurred at mid depth (21 - 40 m).
 
Day: Wednesday, Feb. 3
Time: 04:30 - 04:45pm
Location: Sweeney Center
 
Code: SS09WE0430S