The spermatid pathway and associated reproductive structures of the squat lobster thenus orientalis (Lund, 1793)

Abstract

This study describes and identifies the relationship between sperm development and associated structures of the male reproductive system of the Scyllarid lobster Thenus orientalis. The male gonad of Thenus orientalis consists of paired testes, each with a vas deferens which terminates in a gonophore on the coxopodite of the fifth pereiopod. Internally the testis consists of numerous acini which are attached to coiled anterior and posterior collecting tubules. Within the acini, spermatogenesis occurs giving rise to spermatids which are liberated into the collecting tubules and subsequently grouped into spermatophores. Spermiogenesis continues as the spermatophores progress through the proximal, medial and distal vas deferens where maturity is reached. Movement through the vas deferens is assisted by apocrinal secretions of the glandular epithelium which probably functions both as a nutrient and lubricant. An external layer of smooth muscle which thickens progressively towards the distal vas deferens also assists in propelling the luminar matrix containing the spermatophores toward the gonophore