Spatial and temporal patterns in the Mediterranean populations of &lt;em&gt;Aristaeomorpha foliacea&lt;/em&gt; and &lt;em&gt;Aristeus antennatus&lt;/em&gt; (Crustacea: Decapoda: Aristeidae) based on the MEDITS surveys

Beatriz Guijarro,Kostas Kapiris,Kostas Skarvelis,Maria Cristina Follesa,Sergio Ragonese,Reno Micallef,Isabella Bitetto,Alessandro Mannini,Angelo Cau,Olivera Marković,Gianfranco D’Onghia

doi:10.3989/scimar.05012.04a

Abstract

The aristeids Aristaeomorpha foliacea and Aristeus antennatus are two species of great economic importance in the Mediterranean Sea, where they are exploited almost exclusively by bottom trawlers. We analysed their geographical and inter-annual patterns using data collected, following a standardized protocol, during the MEDITS international experimental bottom trawl surveys. The data used consisted of standardized abundance and biomass indices, size structure and individual biological information collected in the northern Mediterranean for more than two decades. Several univariate and multivariate methodologies were used to analyse the data. The current study confirms previous findings, such as the longitudinal gradient in the relative presence of the aristeids, but also offers additional information for a better understanding of the intrinsic variability of the data over the years and between areas. Moreover, geographical variability in the somatic condition index is discussed, taking into account the role of environmental conditions and fishing pressure. The large geographical variability found for both species in this regional approach reflects the importance of additional studies at a small-scale geographical level. Such studies could be particularly important for managing and ensuring the stability of these species, for which large regional approaches may be inadequate.

Highlights

The giant red shrimp, Aristaeomorpha foliacea (Risso, 1827), and the blue and red shrimp, Aristeus antennatus (Risso, 1816), are decapod crustaceans with a wide geographic distribution in deep waters that frequently share their distribution
For the requirement of the present analysis, the Mediterranean area covered by the Mediterranean International Bottom Trawl Surveys programme (MEDITS) programme was divided into six predefined basins, following the approach carried out by Cau et al (2002) with the first years of the data series (1994-1999) (Fig. 1B; see Table 1 for correspondence between regional area of reference (RAR) and geographical subarea (GSA)): RAR1, Algerian Provencial; RAR2, Tyrrhenian (Tyrrhenian Sea, Ligurian Sea, eastern coast of Sardinia and Corsica); RAR3, Sardinian; RAR4, Strait of Sicily sensu lato; RAR5, Ionian; and RAR6, Aegean (Aegean Sea including the waters around Crete and Cyprus)
A. foliacea was caught in 38.5% (3376) of the hauls and A. antennatus in 28.6% (2510)

Summary

Introduction

The giant red shrimp, Aristaeomorpha foliacea (Risso, 1827), and the blue and red shrimp, Aristeus antennatus (Risso, 1816), are decapod crustaceans with a wide geographic distribution in deep waters that frequently share their distribution. In the Mediterranean, the species show a longitudinal gradient, as A. antennatus is more abundant in the northwestern areas and A. foliacea in the central and eastern ones (D’Onghia et al 1998, Cau et al 2002, Cardinale et al 2017). Both species show genetic divergence between samples from the Mediterranean and other waters. For A. antennatus, Marra et al (2015) considered that no barriers to gene flow exist in the Mediterranean, but Fernández et al (2011) considered the Strait of Sicily as a barrier to gene flow and identified one western Mediterranean stock with significant genetic divergence of samples from the eastern ones

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