Larvae of Echinocephalus were found to infest the visceral organs of the arkshell Scapharca natalensis especially attached to either foot wall of alimentary canal and genital duct. The larvae have an elongated body with rounded head Figure 1A.
Larval Echinocephalus was observed to be attached to different parts of the visceral mass of the host including to the genital duct. Ko (1975) reported similar infestation of Echinocephalus sinensis.
Infusion of contrast medium through the urogenital pore permitted visualisation of both the urethra and genital duct. The genital duct is located ventrally to the urinary system and, in a lateral projection, its course is easily detectable until the area of the gonads (Figure 5).
In both the marine species studied the genital duct and urinary duct exit as two separate ducts into two separate pores.
In 86 cases out of the 95 females that contained one tip in their genitalia, the tip was placed inside the spermatheca, and in nine cases the tip was located in the genital duct
. Thus, we estimated the probability for the first tip in the female's genitalia to enter the spermatheca as 0.9.
It is typical within this group that the gametes are transferred from the gonad to the distal portion of the right kidney through a genital duct, and are released to the exterior through a right kidney opening which opens to the mantle cavity.
The renopericardial duct which carries the gametes from the gonad to the right kidney is referred to from now on as the "genital duct".
The drawing depicts two (apparently undescended) testes, female external genitalia, a vagina, and a genital duct
system that does not resemble a normal uterus and oviducts.
The basic characteristics of the genital ducts
are similar to other tubular organs; that is, the parenchyma consists of concentric layers of tissue: tunica serosa (or tunica adventitia), tunica muscularis, tela submucosa, and mucosa.
It acts on the female genital ducts
and mammary glands to regulate the birthing process and milk secretion.
Minute Yellow-brown granules were also often seen in the epithelia of the genital ducts
Anti-Mullerian hormone A peptide produced by developing Sertoli cells that causes regression of the mullerian ducts in males during differentiation of the genital ducts