Localisation of crustacean hyperglycemic hormone in late embryonic and first larval stage of Nephrops norvegicus (Astacoidea, Nephropidae)

We report here on immunohistochemical studies of embryos of the Norway lobs ter Nephrops norvegicus at 90% development, the stage being assessed accord ing to eye index. The sinus gland was readily identified as a teardrop shap ed structure about 45 mum in length in 90% embryos and as an oval structure about 50 mum in length in post-hatched larvae. Silver enhanced immune-gold staining used with heterologous antiserum against Astacus leptodactylus cr ustacean hyperglycemic hormone showed immunopositive axon endings in the la te embryo and newly hatched larva. In contrast, there was no immune-positiv e reaction with antiserum against Homarus americanus gonad inhibiting hormo ne. This paper represents the first demonstration of early functional diffe rentiation of sinus gland in N. norvegicus and only the second in decapod c rustaceans.