2015): New record for Galba neotropica (d'Orbigny, 1835) in Argentina, with a detailed analysis of its morphology and molecular characteristics, Molluscan Research, We report for the first time the presence of Galba neotropica in Santa Fe province, Pampean Argentina. Until the present work, the identity of the intermediate host of Fasciola hepatica in this region, the most important livestock production area of Argentina, was unknown. This report extends the geographic distribution of G. neotropica and is the first to provide molecular and morphological information on this species in Argentina. During summer 2013, snails were collected on private livestock farms with high prevalence of fasciolosis in cattle. Specimens were identified by using the nuclear sequences of the internal transcribed spacers ITS-1 and ITS-2, the shell and the shape and size of the male reproductive organs. Molecularly, ITS-1 and ITS-2 nuclear sequences exhibit 100% nucleotide identity with G. neotropica from Lima, Peru. Morphologically, G. neotropica from Santa Fe province was indistinguishable from Galba viatrix and Galba cubensis, the other two cryptic species within this South American group of lymnaeids. The combination of molecular and morphological analyses is strongly recommended to identify lymnaeids at species level. The identity of the intermediate host and the subsequent knowledge of its susceptibility, behaviour, distribution, ecology and biology are important components in developing effective measures to control fasciolosis.

Pseudosuccinea columella (Say, 1817) is a widely distributed freshwater lymnaeid snail (Madsen and Frandsen 1989). Its role in the transmission of Fasciola hepatica (Linnaeus, 1758), the causative agent of fasciolosis, has been demonstrated in several countries of South America (

Snails of the family Lymnaeidae, as Pseudosuccinea columella, are the intermediate hosts of Fasciola hepatica, the causative agent of fasciolosis in human and livestock all over the world. A thorough knowledge of snail biology is essential for describing the transmission dynamics and for controlling this disease. Since food quality has had a significant effect on snail growth, fecundity and fertility, in this study we evaluated the use of spirulina (Arthrospira platensis) as a food resource for the artificial breeding of P. columella, an invasive snail and the main intermediate host of F. hepatica in Northeastern Argentina. The main purpose was to measure the effect of spirulina on fitness parameters such as survival rate, growth rate, size at first reproduction, lifetime fecundity and viable offspring. A total of 20 676 newly-laid F 2 eggs were used; half of them were fed with lettuce (treatment L) and the other half with lettuce plus spirulina (treatment L+S). In comparison with P. columella snails fed only with lettuce, we found that P. columella fed with lettuce plus spirulina: 1) showed higher survival rates, 2) grew faster and showed higher growth increments, 3) attained sexual maturity earlier in time (L+S:60 days vs. L:120 days) and at a smaller size (L+S:4.8mm vs. L:8.2mm), 4) had a longer reproductive period (L+S:150 days vs. L:90 days), 5) produced a higher number of eggs/snail (L+S:29.6 vs. L:13.3), and 6) showed a higher offspring hatching rate (L+S:70% vs. L:40%). The supplementation of P. columella diet with commercial spirulina enhances it fitness and improved the artificial breeding of this species. Spirulina may have a direct positive effect on P. columella development by consuming it, along with an indirect positive effect by improving the water quality. This rearing technique provided large number of reproducing adults and a continuous production of offspring, which are essential for developing future experimental studies in order to improve our knowledge on P. columella biology. Rev. Biol. Trop. 63 (2): 479-489. Epub 2015 June 01.