Carbon, nitrogen, hydrogen and sulphur components of intertidal caprellids (Crustacea) from southern Spain

Abstract

Carbon (C), hydrogen (H), nitrogen (N) and sulphur (S) contents were measured in the most common caprellid species inhabiting intertidal ecosystems of southern Spain ( Caprella acan- thifera , C. danilevskii , C. dilatata , C. equilibra , C. grandimana , C. hirsuta , C. liparotensis and C. penantis ). Five gammarid species ( Ampithoe sp., Apherusa sp., Hyale perieri , H. schmidtii and Jassa marmorata ), 3 isopods ( Dynamene edwardsi , Idotea chelipes and Ischyromene lacazei) and the tanaid Tanais dulongii were also collected for comparisons. Univariate analyses showed that S con- tent was significantly higher in caprellids (mean ± SD; 1.5 ± 0.3%) than in gammarids (1.1 ± 0.1%), isopods (0.9 ± 0.2%) and tanaids (0.9 ± 0.3%), and N showed significantly higher concentrations in caprellids (6.0 ± 0.9%) and gammarids (6.2 ± 0.5%) than in isopods (5.2 ± 0.8%) and tanaids (5.4 ± 0.4%). The average of the C and H contents by dry weight was 27.2 ± 3.1 and 4.6 ± 0.4%, respec- tively, in caprellids, 28.2 ± 2.3 and 4.7 ± 0.3% in gammarids, 26.8 ± 3.0 and 4.2 ± 0.5% in isopods and 26.4 ± 2.0 and 4.2 ± 0.3% in tanaids. The first axis of the principal component analysis associated with the concentrations for the 17 peracaridan species accounted for 69.7% of the total variance and cor- related significantly with C, H and N, while the second axis accounted for 25.1% of the variance and correlated with S. Caprellid females showed higher concentrations of C, H, N and S than males, but analysis of variance only showed significant differences in the percentage of C and H. The higher C and H contents in females could reflect a larger accumulation of lipids in the body and could be related to reproduction and differences in feeding habitats between males and females.