Search

The native terrestrial snail fauna of the Hawaiian Islands faces numerous threats that have led to severe range reductions, population declines, and extinction of species. With the continued declines of many wild populations, a crucial component of preserving Hawaiian terrestrial snail biodiversity is through captive rearing programs, like that implemented by the Hawai‘i Department of Land and Natural Resources Snail Extinction Prevention Program. Rare and endangered tree snails in the family Achatinellidae, which feed on epiphytic microbial communities, are maintained in captivity with a diet that includes native vegetation brought in from nearby forests, as well as a cultured fungus originally isolated from native host trees. Recent mortality events in lab populations have been attributed to wild-gathered vegetation. These events have increased interest in developing a completely manufactured or cultured diet that would eliminate the need for exposure to wild-gathered plants. This study compared survival and egg production in Auriculella diaphana provided with lab-cultured fungus, and those provided with wild vegetation. We compared the number of eggs laid and number of deaths among three treatments: (1) wild collected vegetation only; (2) wild vegetation supplemented with laboratory-cultured fungus; and (3) laboratory cultured fungus only. Mortality did not significantly differ among treatments, but the number of eggs laid was significantly higher in snails provided wild vegetation and cultured fungus (F = 24.998; P < 0.001), compared with those provided with only wild vegetation (t = 1.88, P = 0.032) or only cultured fungus (t = 4.530, P = 0.004). Our results suggest: (1) the existing strain of cultured fungus alone is not sufficient to maintain captive-reared snail populations; (2) the additional energy or calcium provided by the cultured fungus appears to enhance egg reproduction in captive-reared populations; (3) the presence or absence of live vegetation influences snail behavior, including aestivation and egg laying. These results highlight the importance of ongoing research to culture additional species of fungi at a rate that could support captive-reared populations, as the diversity of fungi present in wild epiphytic microbial communities may be important for snail reproductive health. [ABSTRACT FROM AUTHOR]

Tree snails in the family Partulidae are widespread across the tropical Pacific, with endemic species occurring on most high islands. Partulid species have faced catastrophic range reductions and extinctions due primarily to introduced predators. Consequently, most extant species are threatened with imminent extinction. The U.S. administered Mariana Islands, consisting of Guam in the South and the Commonwealth of the Northern Mariana Islands (CNMI) in the north, historically harbored six endemic partulid species, half of which are thought to be extinct. While conducting a phylogenetic assessment of Partula gibba, an extant tree-snail with a range spanning at least seven islands within the archipelago, it was discovered that what has been identified as P. gibba on the island of Rota is a misidentified cryptic species. Here we use molecular phylogenetics, shell morphometrics and reproductive anatomy to describe it as a new species, Partula lutaensis sp. nov.. Because the new species has suffered population declines and has a restricted range, consisting solely of the small island of Rota, we highlight the urgent need for conservation measures. [ABSTRACT FROM AUTHOR]