Vol. 48 No. 1, 2009

Diversity of Hyperiid Amphipods (Crustacea: Peracarida) in the Western Caribbean Sea: News from the Deep

Rebeca Gasca*

El Colegio de la Frontera Sur (ECOSUR), Unidad Chetumal, A.P. 424, Chetumal, Quintana Roo 77014, Mexico

Rebeca Gasca (2009) Previous surveys of hyperiid amphipods from the western Caribbean were largely restricted to the epipelagic layer (0-200 m in depth).  The need for deeper sampling in the area has been recognized in some work; presumably, this strategy would significantly increase knowledge of the local and regional diversity of this and other zooplankton taxa.  Hyperiid amphipods collected at an expanded sampling range (0-940 m) in Mexican waters of the northwestern (NW) Caribbean, were taxonomically analyzed.  Samples were collected during 2 cruises (2002 and 2006), using different sampling gear on each one.  In total, 92 hyperiid species were found; 32 species had not hitherto been recorded in the area, thus increasing (from 60 to 92, 50%) the number of species currently known in this part of the Caribbean.  Some of these species were recorded for the first time in the NW Caribbean or in Mexican territorial waters.  A greater relative increase was observed among the Physosomata, a group known to contain mainly meso- and bathypelagic forms.  A revised, expanded checklist of the hyperiids of the NW Caribbean is also provided; this area is now among the best studied in the NW tropical Atlantic, which in turn still has a low number of records compared to other regions of the world.  These results confirm that 1) significant increases of local and regional lists of hyperiids may be expected from more sampling efforts in deeper layers, and 2) this and other groups of tropical oceanic zooplankton deserve further study in this environment.

Key words: Marine biogeography, Zooplankton, Mesopelagic, Tropics, Biodiversity.

*Correspondence:  E-mail:rgasca@ecosur.mx