Physa Marmorata Guilding, 1828 (Pulmonata: Physidae)

Abstract

A description of Physa marmorata Guilding, 1828, based on material collected at its type-locality, the Caribbean island of Saint Vincent, is presented. The shell is thin, horn-colored, surface very glossy, diaphanous. Spire acute, elevated; protoconch distinct, rounded-conical, reddish-brown; five not shouldered, broadly convex whorls with subobsolete spiral lines and thin growth lines. Aperture elongated, 1.4-2.0 times as long as the remaining shell length, narrow obovate-lunate; upper half acute-angled,lower half oval,narrowly rounded at the base, outer lip sharp, inner lip completely closing the umbilical region; a very distinct callus on the parietal wall; columellar lip with a low ridge gradually merging into the callus. ratios: shell width/shell length = 0.44 - 0.52 (mean 0.47); spire length /shell lenght = 0.33-0.41 (mean 0.39); aperture length/shell lenght = 0.59-0.67 (mean 0.62). Oral lappets laterally mucronate, foot spatulate with deeply pigmented acuminate tail. Mantle reflection with 6-10 short triangular dentations covering nearly half the right surface of the body whorl, and 4-6 covering a part of the ventral wall. Body surface with tiny dots of greenish-yellow pigment besides melanin. Renal tube tightly folded in toa zigzag course. Ovotestis diverticula acinous, laterally pressed against each other around a collecting canal. Ovispermiduct with well-developed seminal vesicle. oviduct highly convoluted, merging into a less convoluted nidamental gland which narrows to a funnel-shaped uterus and a short vagina. Spermathecal body oblong, more or less constricted in the middle and somewhat curved; spermathecal duct uniformly narrow, a little longer than be body. About 20 prostatic diverticula, simple, bifurcate or divided into a few short branches, distalmost ones assembled into a cluster. Penis long, nearly uniformly narrow; penial canal with lateral opening about the junction of its middle and lower thirds. Penial sheath with a bulbous terminal expasion the tip of which isinserted into the caudal end of the prepuce. Prepuce shouldered, much wider than the narrow portion of the penial sheath. Penial sheath/prepuce ratio about 2.08 (1.45-2.75). The main extrinsic muscles of the penial complex are a retractor, with a branch attached to the bulb, and another to the caudal end of the penial sheath; and a protractor, with a branch attached to the shoulder of the prepuce and adjoining area of the penial sheath, and another to the caudal end of the penial sheath. Egg capsule C-shaped, with 10-30 elliptical eggs (snails 10mm long) measuring about 1.10 mm (0.90-1.32) through the long axis and surrounded by an inner and an outer lamellate membranes. Jaw a simple obtusely V-shaped plate. radula will be described separately.<br>É apresentada uma descrição da espécie physa marmorata Guilding, 1828, baseada em material coletado na sua localidade-tipo, a ilha Saint Vincent, no Caribe. A concha é delgada, de coloração córnea, superfície muito lustrosa, diáfana. Espira aguda, elevada; protoconcha distinta, cônica-arred...

The population density of Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) an intermediate host of Fasciola hepatica (Linnaeus, 1758), in the Caparaó microregion, ES, Brazil

“…All procedures were performed manually with specific equipment such as sieves, nettings and filters. After collection, the molluscs were sent to the parasitology laboratory of the Hospital Veterinário da Universidade Federal do Espírito Santo (HOVET-UFES), where they were separated according to points, counted and identified according to Paraense (1975Paraense ( , 1983Paraense ( , 1986. Samples of L. columella were directly exposed to artificial light for four hours and then analysed to determine the presence of larval form of F. hepatica.…”

Planorbidae, Lymnaeidae and Physidae of Argentina (Mollusca: Basommatophora)

“…Physa marmorata Guilding, 1828 -Ponds at Resistencia (Chaco); ditch at Corrientes (Corrientes); marshes at Campana and Tigre; ditch between Ensenada and La Plata; pond at Vuelta de Obligado (Buenos Aires). Morphology in Paraense (1986b).…”

The Architecture of the Physid Musculature ofPhysa acutaDraparnaud, 1805 (Gastropoda: Physidae)

“…1A) and its insertion is, as shown in Fig. 1B, on the lower right hand side of the mantle (Harry & Hubendick 1964;Paraense 1986Paraense , 1987. The point of insertion is clearly visible as an elongate scar on the mantle, broadest close to the mantle collar and extending towards the mid-dorsal line, but tapering as it does so.…”

“…(1) Snails were placed in fresh water with small pieces of tobacco for five to six hours at room temperature and then at 4°C in a refrigerator until they showed no signs of movement; they were then placed in 70 % ethanol. (2) Snails were kept overnight in a 0.05 % Nembutal solution after which they were placed in water at 70°C for ±40 seconds in order to kill them; the soft parts were then pulled from their shells and placed in a modified Railliet-Henry solution (Paraense 1986(Paraense , 1987. Although both methods were effective, the physid musculature proved easier to dissect and follow in snails relaxed using method 1.…”

“…Harry (1964) used the presence of the physid musculature as the main character separating the Physidae from the rest of the Basommatophora. Paraense (1986Paraense ( , 1987 identified the attachment (insertion) of the "physid muscle" in his re-descriptions of Physa marmorata Guilding, 1828 and Physa cubensis Pfeiffer, 1839 respectively. He did not comment further on this beyond noting that the roof of the pulmonary cavity was darkly but patchily pigmented except for that part covering its attachment which in the case of P. marmorata was lightly pigmented or unpigmented and in the case of P. cubensis, always unpigmented.…”