Sluys and Cannon, 1989
Overview
Diagnosis: Jugatovaria polynesia Sluys and Cannon, 1989 differs from its congener, J. spinosa, in the presence of dorsal testes which extend into the posterior end of the body, and in the relatively posterior position of the ovaries.
Habitus: Preserved specimens up to 4 mm long and 1 mm wide. Unpigmented body lanceolate, with rounded front and hind end.
Alimentary System
The short pharynx is situated in the anterior half of the body and measures about one-eight of the body length. The anterior section of the pharynx has a somewhay oblique orientation, due to the dorsal insertion of the root of the pharynx. The mouth opening is at the anterior end of the pharyngeal cavity.
The anterior ramus of the intestine extends anteriorly to the eyes and the brain as an undivided branch, and gives off about 4 pairs of postocellar diverticula. Each of the long posterior gut trunks gives rise to about 26 lateral diverticula; the posterior rami do not meet in the posterior end of the body.
Male Reproductive System
The rather small and relatively numerous testes are principally dorsal, and extend from directly behind the ovaries far into the posterior of the body. The vasa deferentia expand to form voluminous false seminal vesicles, but decrease abruptly in diameter just before penetrating the penis bulb. Here, the vasa deferentia open into the dorsal section of a large, intrabulbar seminal vesicle which receives an abundant secretion from penis glands. The seminal vesicle opens into the ejaculatory duct, the lining epithelium of which carries numerous sclerotic spines.
The musculature of the penis bulb is well developed. The penis papilla has well developed layers of circular and longitudinal muscles. Strong, longitudinal retractor muscles traverse the papilla and attach to the ejaculatory duct.
Female Reproductive System
The vitellaria are well developed, occupying the entire space between ventral and dorsal body surface; vitelline follicles extend from anterior to the ovaries far into the posterior of the body.
The relatively small ovaries are situated immediately in front of the root of the pharynx and, consequently, at a considerable distance behind the brain. The oviducts arise from the anterolateral surface of the ovaries, after which they bifurcate to give rise to a short anterior branch and a posteriorly running section. Immediately anterior to each of the ovaries lies a poorly delimited parenchynatic sac, which communicates with the gonads through an irregularly shaped and weakly muscular duct. This duct arises from the anterodorsal surface of the ovaries.
No trace of the posterior oviducal branches could be discerned in the posterior end of the body. However, the oviducts presumably unite into a long common oviduct, which opens into a short female genital duct. The last-mentioned is surrounded by circular and longitudinal muscles and receives the secretion of shell glands.
Eyes
The unicellular eye cups have no lens; the number of retinal cells in each pigment cup could not be determined.
Ecology
The type specimens of J. polynesiana were collected from the junction between cephalo-thorax and abdomen of a specimen of the double spined coral lobster Panulirus pencillatus. Specimens of the triclad may occur also on the external shell and on the ventral abdomen of the lobster.
Distribution
It is known only from the type locality: Lifuka Island, Kingdom of Tonga.
Material Examined, Type Material
Q.M.: Holotype: GL 10095, sagittal sections on 2 slides. Paratypes: GL 10094, whole mount; GL 10093, sagittal sections on 10 slides.