Structural changes of the spermatophore in the freshwater “red claw” crayfish Cherax quadricarinatus (von Martens, 1898) (Decapoda, Parastacidae).

LOPEZ GRECO, L.S. Y F.L. LO NOSTRO

ACTA ZOOLOGICA

BLACKWELL SCIENCE

Lugar: STOCKHOLM; Año: 2008 vol. 89 p. 149 - 155

0001-7272

The structure of the spermatophore (SF) was studied in Cherax quadricarinatus. Pieces of the distal vas deferens (DVD) and transferred SF from the females were collected, fixed, cut and stained. Within the DVD, the primary layer (PL) and the secondary layer (SL) of the SF were distinguishable. In this latter two components were detected: citoplasmatic drops (CD) and a homogenous matrix (M). During the first ten minutes post extrusion the CD drastically changes looking like “empty drops”; at this time SF change from a liquid stage to a sticky one. One hour after extrusion the SF began to harden and within the first 24-48h postmating (PM) it is a solid and intense white colour structure tightly attached to the female; after 72h it acquires slack aspect and begins to disaggregate occurring its complete dehiscense between 96-120h PM. Histologically, the PL maintains its integrity surrounding the spermatozoa while the SL loses the CD. The SF begins to hydrate between 24-48h while since 72-96h many section of the sperm cord began to coalesce. From 48h PM some fissures begin to appear within the matrix that enlarged between 72-120h. We proposed that both manipulation by the female and hydration are the mechanisms involved in the releasing of the spermatozoa from the SF.