Crustacean larvae. (Photo Credit: IEO)
Crustacean larval stages outlined at Balearic Sea
Thursday, April 25, 2013, 00:50 (GMT + 9)
A team of scientists from the Balearic Oceanography Centre of the Spanish Institute of Oceanography (IEO), of Spain, and from the Instituto Português do Mar e da Atmosfera (IPMA), from Portugal, found larval stages of several species of decapod crustaceans in the Balearic Sea, which have proved to be of interest to marine biodiversity and fisheries exploitation.
To date, no information has been available about it, the IEO stated.
As part of this research, published in the journal Scientia Marina, the experts were able to describe the larval stage of the red shrimp (Aristeus antennatus), hitherto unknown, and thoroughly re-describe the first stage of development of the cicada (Scyllarides latus), which had been described very succinctly almost a century ago.
The researchers have also reported the capture of the deepwater rose shrimp (Parapenaeus longisrotris) larvae in the second protozoea status and the presence of the first zoea of an endangered species in this area, such as is the case of the spider crab (Maja squinado).
The spider crab is subject to a restocking programme in the Balearic Islands while decapod crustaceans are target species of the bottom trawl fishery and of some small-scale fishing modes in the western Mediterranean.
While these resources are economically important, and in adulthood have been the target of numerous studies and research projects, most of their larval development stages are unknown.
Two oceanographic research surveys have been performed around the Balearic Islands and hundreds of plankton samples have been collected, which were used by scientists to study the decapod crustacean larvae.
Out of the over 7,000 larvae that have been analyzed, only seven were for these species. Although it is a low number, the finding is important for several reasons.
"The presence of larval forms in the plankton samples, especially considering that they are early stages, suggests the reproduction of their corresponding adult specimens in the study area," explains Asvin Pérez Torres, lead author of the work.
In the case of the spider crab, that fact "could demonstrate that the programme conducted for their re-stocking in the Balearic Islands is working," continued the researcher.
It is anticipated that this new study will permit future taxonomic identification from plankton samples.
"The fact that the samples were obtained at different times of the year, at various depths throughout the water column and in two stations of the continental shelf and the mid-slope through the north and south of Mallorca, helps to expand the knowledge about the spatiotemporal distribution of decapod crustacean larvae," pointed out the IEO.
According to Perez Torres, "Finding larvae of those species whose adults live in contact with the bottom on the surface layers, and in the case of the deepsea red shrimp, makes it possible to rule out the hypothesis that planktonic forms of these species remain in deep areas, close to the adult specimen distribution zone."
This research was conducted in the framework of the research project Structure and Dynamics of the Slope Benthopelagic Ecosystem in Two Oligotrophic Areas of the Western Mediterranean: a Multidisciplinary Approach and at Different Time Scales in the Balearic Islands, funded by the National R+D+i plan.
By Analia Murias