Long-term variations in nutritional condition of Panulirus argus (Decapoda: Palinuridae) in Cuba: analytical and morphological approaches

Abstract

Nutritional condition indices have been frequently used as morphophysiological indicators to study variations on lobster's physiology and energy reserves. This study was aimed to determine long-term spatio-temporal variations in nutritional conditions of Panulirus argus (hereinafter – lobster), considering two indices, namely the analytic Blood Refractive Index (BRI) and the morphometric Kcl (total weight / carapace length relationship). Information from eleven sites in the Caibarién region, sampled in 2010–2015, and twelve sites in the Batabanó region, sampled in 2011–2017, were named as the Current Period. Morphometric data for Kcl estimation, including 1987–1988 in the Caibarién region, and 1981–1993 in the Batabanó region, were grouped as the Past Period. Temporary variations were determined comparing Past and Current periods at each region. Spatial variations were determined by comparing the data between the two regions. For analysed lobsters in the Current period, we determined BRI = 14.3, Kcl = 7.0 in the Caibarién region, and BRI = 15.2. Kcl = 7.0 in the Batabanó region. For the Past period, the Kcl value was 5.8 and 6.3 in the Caibarién and Batabanó region, respectively. Both Kcl and BRI indices were higher for male individuals. This could be associated with the reproductive process, and intrinsic morphometric differences between sexes could influence though. Morphometric parameters were higher for the Current Period. Spatial variations of morphometric parameters were significantly different for the Past Period, which were attributed to different environmental conditions in each region. The BRI index was higher in the Batabanó region, which was possibly associated with the better status of the benthic communities and the better water quality. Present results contribute to understanding lobster's nutritional condition in natural habitats, mainly in the Caibarién region, where few studies have been carried out to date.