IN THEORY, SNAILS CAN COME IN TWO ENANTIOMORPHS: either dextral (coiling clockwise) or sinistral (coiling counter-clockwise). In snail species where both forms are actually present, coiling direction is determined by a single gene with delayed maternal inheritance; there is no predictable relationship between a snail's own coiling genotype and its actual coiling direction. Because of this genet...

Parglogenia cobourgensis sp. nov. , a new species of camaenid land snail is described from Cobourg Peninsula, Top End the Northern Territory in Australia. This has shell that identical to type genus, pelodes which also occurs End. However, both clearly differ their reproductive anatomy and are well-differentiated terms mitochondrial phylogenetics. A single specimen Croker Island, West Arnhem La...

Recent field surveys on snails conducted in the oriental region of Morocco have led to discovery a new species belonging genus, described here as Znassela bnisnasensis gen. et sp. nov. It can be distinguished from other hydrobiid by morphology shell and male anatomy. The snail differs mainly its elongated ovate with 4.5 whorls, slightly convex shallow suture, penis showing swelling near tip; la...

The length-weight relationship and condition factor have been broadly investigated in snails to obtain the index of physical condition of populations and evaluate habitat quality. Herein, our goal was to describe the best predictors that explain Achatina fulica biometrical parameters and well being in a recently introduced population. From November 2001 to November 2002, monthly snail samples w...

A high degree of intraspecific variation, both genetic and in shell morphology, of the operculate land snail Cyclophorus fulguratus (Pfeiffer, 1854) suggests that its classification as a single species warrants reconsideration. We sequenced two nuclear (18S and 28S) and two mitochondrial (16S and COI) genes of 46 C. fulguratus specimens and used them to estimate the phylogeny and to determine t...

Doses of 60Co gamma radiation with 2.5; 5; 7.5; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 80; 160; 320 and 640 Gy were applied to 1, 080 snails Biomphalaria straminea, an intermediate host of Schistosoma mansoni, divided in groups containing 30 mollusks. In addition, 60 non irradiated snails were kept as control. Fifty percent of the population was kept in colonies (allowing cross fertilizati...

Aim. External fertilisation requires synchronisation of gamete release between the two sexes. Adequate synchronisation is essential in aquatic media because sperm is very short-lived in water. In the cichlid Lamprologus callipterus, fertilisation of the eggs takes place inside an empty snail shell, where females stay inside the shell and males have to ejaculate into the shell opening. This spaw...

Females of the Lake Tanganyika cichlid Lamprologus callipterus exclusively breed in empty snail shells that males collect in their territories. Male–male competition for shells is severe, leading to frequent shell stealing and territory takeover. As a consequence, males have breeding females in their shells that spawned with competitors. In this field study, we investigated both naturally occur...

The existence of consistent individual differences in behaviour ('animal personality') has been well documented in recent years. However, how such individual variation in behaviour is maintained over evolutionary time is an ongoing conundrum. A well-studied axis of animal personality is individual variation along a bold-shy continuum, where individuals differ consistently in their propensity to...

Abstract We find an unifying approach to the analytic representation of domain bounded by a generalized Pascal snail. Special cases as snail, Both leminiscate, conchoid Sluze and disc are included. The behaviour functions related snail is studied.