The extent of anatomical malformations is dependent on the concentration of TBT in the environment (Gibbs & Bryan, 1986) and can range from mild, forming a pseudopenis primordium to very severe obstruction of the gonoduct
(Oberdorster & McClellan-Green, 2002).
In individuals having a gonad predominated by oogenic tissue and various developmental stages of oocytes, a small region appearing identical to inactive (non-secreting) TG tissue was present in the caudal region of the gonad closest to the gonoduct
2015) considering the stages (and steps) of the germ cell differentiation, predominant type of germ cell, repletion of gonadal tubules, and the presence of mature germ cells in the gonoduct
In the spawning season some post-ovulatory follicles had an opening to the ciliated gonoduct
through which mature oocytes had been released (Fig.
Ziegenhorn & Thiem determined that the reproductive system in Fissurella crassa Lamarck, 1822 consisted of a gonad that opened to the right kidney through a gonoduct
which contained a gland in its internal wall, and which was also observed in females of Fissurella oriens Sowerby, 1835 (under Fissurella alba Philippi, 1845) and Fissurella limbata Sowerby, 1835.
On the posterior part, the ovaries continue in a short gonoduct
A similar observation that was also characterized by an intense hemocytic response by a Crassostrea gigas oyster was speculated to be a consequence of an atypical copepod invasion via the oyster's gonoduct
(da Silva et al.
The presence of spermatozoa at the posterior end of the female gonoduct
demonstrates that sperm either swim or are transported deep into the reproductive system.
The distribution of precursors and biosynthetic enzymes required for Tyrian purple genesis in the hypobranchial gland, gonoduct
, an egg masses of Dicathais orbita (Gmelin, 1791) (Neogastropoda: Muricidae).
The female reproductive system is a bilaterally symmetrical, H-shaped structure in the antero-lateral portion of the cephalothorax, composed of ovaries, which run to the posterior, joined by a transversal commissure in the antero-lateral portion of the cephalothorax, gonoducts
(Figure 2a) and a specialized dilation of the gonoduct
, known as the spermatheca.
3), including early spermatogenesis (ES), characterized by abundant vesicular connective tissue spermatogonia and spermatocytes attached to follicle walls; late spermatogenesis (LS), characterized by increased spermatids and sperm in the testis and a small amount of connective tissue; spermiogenesis (SG); SP, characterized by the presence of sperm in the gonoduct
, empty follicles, and the reincorporation of vesicular connective tissue; and postspawning (PS), characterized by reabsorption and increased levels of connective tissue.
In free-spawning invertebrates, the eggs and sperm, having passed through a gonoduct
and gonopore, are released directly into the water column.