Frontal Horns and Associated Gland Cells of the Nauplii of the Barnacles, Balanus Hameri, Balanus Balanoides and Elminius Modestus (Crustacea:Cirripedia)

Abstract

Frontal horns are prominent structures, characteristic of the nauplii of most cirripedes. Such horns are more prominent amongst the Lepadomorpha, i.e. Lepas (see Groom, 1894).Reference is made to frontal horns in those papers concerned with the identification of nauplii (Nilsson-Cantell, 1921; Herz, 1933; Bassindale, 1936; Batham, 1946; Pyefinch, 1948; Buchholz, 1951; Barnes and Barnes, 1959a, b), but more detailed descriptions of horns and associated gland cells are limited to the studies of Groom (1894), Kaufmann (1965) and Walley (1969).In the present study, the morphology of the frontal horns and the cytology of associated frontal horn gland cells of three barnacle species - Balanus hameri (Ascanius), Balanus balanoides (L.) and Elminius modestus Darwin were investigated.