HISTOLOGIA DA GLÂNDULA OVIDUCAL DA RAIA-DE-LA PLATA, Atlantoraja platana (GÜNTHER, 1880) (CHONDRICHTHYES, RAJOIDEI)

Histology of the oviducal gland of the La Plata skate, Atlantoraja platana (Günther, 1880) (Chondrichthyes, Rajoidei)

Abstract

In elasmobranchs, the oviductal gland is a complex structure located between the anterior oviduct and the uterus. This study aimed to understand the anatomical and histological aspects of the oviductal gland of the adult female of the skate Atlantoraja platana. Samples were submitted to AB (Alcian Blue) stains at pH 1.0 and 2.5; as well as PAS (Schiff Periodic Acid Reaction), hematoxylin and eosin (HE) and (carmin best). The anterior oviduct is represented by an outer layer (tunica serosa) and a smooth muscle layer (circular and longitudinal), showing positive reactions with PAS and AB of pH 1.0 and 2.5. The club and papillary zones were responsible for the production of cytoplasmic substances PAS+ and AB+ at pH 1.0 and 2.5. The baffle zone contains spinnerets, which communicate the inner serous secretory tubules with the lumen. In addition, the baffle zone was the region of the gland where the highest concentration of spermatozoa was registered. In the most distal region of the terminal zone, the presence of serous, mucous and mixed secretion tubules was observed, presenting a ciliated pseudostratified cylindrical epithelium, with goblet cells (PAS+, AB+). Due to its high complexity and histophysiological functionality, the oviducal gland of sharks and rays can be considered the key element of reproduction.

Keywords: oviparity, reproductive strategy, reproductive duct, morphology.