Aspects of biology of Megalobulimus paranaguensis (Gastropoda, Acavoidea) in the coastal plain of the Brazilian southeast

Abstract

ABSTRACT. We studied the reproductive biology of Megalobulimus paranaguensis (Pilsbry & Ihering, 1900), a large and long-lived land gastropod from the Atlantic Rainforest of Brazil. The study was conducted at an urban park in the city of Santos, state of São Paulo. For 4 years, we counted the egg postures and annual eclosion rate of 32 captive snails and looked for associations between egg posture and the climatical variables of the period. The annual mean posture of 8.7 eggs per snail obtained in our results is a small number, but typical of Brazilian macromollusks. The annual eclosion rate was 31%. The beginning of the annual activity period of snails occurred in the middle of March, and lasted 33.97±3.02 weeks. The dormancy period started in the beginning of November, and lasted 18.39±3.11 weeks. There were two egg posture peaks, a minor peak between March and May, and a major peak between August and November, with greater values in September. Megalobulimus paranaguensis has a well-defi ned seasonal reproductive pattern infl uenced by environmental temperature and temperature range. Furthermore, in this snail, reproduction is negatively infl uenced by temperature increasing and temperature range.

Additions to the genus Anthinus occurring in Minas Gerais and Goiás regions, Brazil, with description of five new species, one of them in the new related genus Catracca (Gastropoda, Eupulmonata, Strophocheilidae)

“…A phenotypical base to understand the relationship of the Strophocheilidae with the other related families is also difficult for the same reason–lack of anatomical knowledge. At the time Strophocheilidae was only closely related to Dorcasiidae (African) and Acavidae (Asian) within Acavoidea [ 9 ], a group that apparently lays large eggs, produced by a thick walled, glandular spermoviduct, the phenotypic analysis was difficult. The scenario became more complicated with the present conception of these families as part of Rhytidoidea, with five additional families, based on molecular approaches [ 11 , 12 , 32 ].…”

“…proclivis (Martens, 1888) [19]; (8) Me. dryades Fontenelle, Simone & Cavallari, 2021 [20]; (9) Me. oblongus (Mu ¨ller, 1774) and ( 10) Me.…”

“…The family Strophocheilidae has had an unstable taxonomic history [ 4 , 5 ], but usually it has been considered endemic from South America, with relatives in Africa–the Dorcasiidae; and in Asia–the Acavidae; all grouped in Acavoidea (e.g., [ 9 ]), or sometimes in Strophocheiloidea (e.g., [ 10 ]). South American members have traditionally been assigned to two families: Strophocheilidae and Megalobulimidae [ 5 ].…”

Socio-environmental assessment of the impact of the African snail, Lissachatina fulica (Férussac), 1821, on the population of Alto Paraíso de Goiás, Brazil

“…The competition for resources with the exotic and invasive species is unfavorable as the invading species is generalist and has greater chances of surviving in cracks and corners, besides adapting better to anthropic environments, having a higher colonization rate and bringing the native species to lethargy and death days after contact (Eston et al, 2006). According to Fontenelle and Miranda (2017), the Megabulimus spp are part of a group of giant neo-tropical terrestrial snails known as Aruá-domato, with 63 different species in Brazil. They have nocturnal habits, spending days in dormancy; long life; low population density with small reproductive potential, with a maximum of five eggs per copulation, per individual (Fontenelle & Miranda 2017).…”

“…According to Fontenelle and Miranda (2017), the Megabulimus spp are part of a group of giant neo-tropical terrestrial snails known as Aruá-domato, with 63 different species in Brazil. They have nocturnal habits, spending days in dormancy; long life; low population density with small reproductive potential, with a maximum of five eggs per copulation, per individual (Fontenelle & Miranda 2017).…”