Strombus

1-8

Authors: Spotorno, P.; Tâmega, F.T.S.; Bemvenuti, C.E.

Literature and malacological collection records were reviewed to compile a list of the Vermetid taxa from Brazil. The total number of taxa so far recorded is 16: 2 of Dendropoma, 10 of Petaloconchus, 1 of Thylaeodus and 3 of Thylacodes. The present study registered new occurrences of Vermetidae for the Brazilian coast, broadening the knowledge of the group as well as the geographical distribution of these taxa.

15-22

Authors: Fontenelle, J.H. & Miranda, M.S.

The aim of this study was to estimate the age of a population of Megalobulimus paranaguensis (Pilsbry & Ihering, 1900), in an urban park in the Santos / SP on the Atlantic costal forest of southeastern Brazil. During the period of 2000 to 2010, the outer lip of snails marked and recaptured was measured, to estimate its growth rate. Non-linear models were used to determinate the relationship between the lip and age. With these values a von Bertalanffy function were made, and sections of the lip were made to see its internal structure. The following equations were developed: Age = 0.6633 L1.8095 and Error = 0.6144L0.7528. The older individuals observed with lip of 6.5 mm had the age of 19.6 years old. The maximum size calculated for the population was estimated in 8.59 mm, size which age was 32.5 years, with a low growth rate. With the sexual maturity time up to three years, it’s possible that this species may reach 35.5 years old, possible one of highest age for neotropical gastropods. In the sections were found deposition layers relatively homogeneous with mean thickness of 0.076 mm, reunited in bundles with reduction of layers number with the increase of age. The results indicate that shells of Megalobulimus can be used for environmental monitoring.

28

Authors: Strombus

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