Amusium Balloti Research Articles

A larval ascaridoid nematode from Queensland scallops

Cannon L. R. G. 1978. A larval ascaridoid nematode from Queensland scallops. International Journal for Parasitology 8: 75–80. The morphology of a fourth stage larval ascaridoid found in Amusium balloti is given with observations on the double nature of the excretory system. The infection rate was 5.6% with rarely more than one worm per scallop. No seasonal change in incidence was detected and no change in incidence with host size. The systematic position, possible life cycle and economic importance of the worm are discussed.

A Successful Marking Method for the Saucer Scallop Amusium balloti (Bernardi)

Wired-on Petersen discs, tags of monel metal, titanium and plastic attached with δ-cyanoacrylate adhesive, Epitar patches over plastic tags, and Epitar numbers were tested in the search for a suitable field method by which to mark the scallop A. balloti for growth and movement studies. A plastic tag stuck on with δ-cyanoacrylate, an adhesive which hardens in sea water, had the lowest mean probability of loss in recoveries up to 17 months after release. The other advantages of this method were: (1) there was no damage to the shell or organism, (2) the method was quick, which minimized exposure to air, (3) the colour range available in the tags enabled coding of release date and area and the option of either blending or contrasting with the scallop's natural shell colours, and (4) there was no need to record shell height at release (experiments 7-11). The short lifespan of this scallop (about 4 years) prevented the attainment of information over longer periods.

Ascaridoid nematodes of amphibians and reptiles: Sulcascaris

ABSTRACTThe genus Sulcascaris is upheld and redefined. Sulcascaris sulcata from Chelonia mydas and Caretta caretta is redescribed, from Rudolphi's type material and material from the Mediterranean and Western Pacific, demonstrating that the excretory pore opens between the subventral lips and that the excretory cell is bilateral, comprising a short filamentar right component and a more capacious ribbon-like left component containing the nucleus. The phylogenetic significance of this form of excretory system occurring in an ascaridoid of a marine reptile is discussed. It is concluded from comparative studies, based on measurements, sections and electron scanning micrographs, that fourth stage larvae of S. sulcata collected from the stomach of turtles are identical with fourth stage ascaridoid larvae found in the adductor muscle of scallops (Amusium balloti and Chlamys sp.) and that turtles become infected with this species by eating bivalves. Adult S. sulcata were obtained from tank-reared C. caretta fed with encapsulated larvae from scallops.