An Early Stage in Development of Escae and Caruncles in the Deep-Sea AnglerfishCryptopsaras Couesi(Pisces: Ceratioidei)

Abstract

The glandular epithelium of both escae and caruncles originates from a solid, branched ingrowth of epidermal cells from the distal surface of the bulb-shaped light gland primordia in the larva. The lumina within the glandular epithelium appear to originate by the breakdown of the central cells within the solid mass of epithelial cells. An epithelium-lined duct connecting the central glandular lumina with the distal surface of the bulb-shaped primordium was seen only in sections of the posterior esca. This suggests that the intraglandular lumina are formed before the duct to the surface, which then develops within an initially solid strand of cells.