Life cycle of Cyclestheria hislopi (Baird, 1859) (Crustacea, Branchiopoda)

Abstract

The Conchostraca (clam shrimps) are a group of microcrustaceans found in freshwater habitats. They inhabit the benthos, yet many can swim actively and are often associated with macrophytes. They are filter-feeders, deriving their food from suspended particles or solids stirred up from the bottom. In Brazil, five species have been recorded and the life cycle of one of these, Cyclestheria hislopi (Baird, 1859) was investigated in this study. Specimens were collected from fish-farming tanks in upstate São Paulo and from the floodplain of the Miranda River, in the Mato Grosso swamplands of center-west, Brazil. We determined the following variables: post-embryonic development, duration of life cycle (longevity), mean period between broods, duration of instars and individual growth. Taxonomic features of the Cyclestheria sp. specimens from Mato Grosso were also assessed to check the possibility that they belonged to another species of the same genus or a separate ecotype of C. hislopi.

Effects of different feed types and light intensity levels on the growth and reproduction of clam shrimp, cyclestheria hislopi (Baird, 1859)

“…The longevity of female clam shrimp also significantly longer (p<0.05) at light intensity of 0 µmol m -2 s -1 compared to 60, 45 and 30 µmol m -2 s -1 . At 0 µmol m -2 s -1 , longevity of female was 52.33±3.51 days; likewise the culture of same species by Yashima et al [16] also showed female longevity from 52 to 70 days.…”

“…(2 -6 µm) might also be a reason that led to the successful culture of C. hislopi. Similar to Yashima et al [16], they cultivated C. hislopi successfully by using chlorophycean Pseudokirchneriella subcapitata (8 -12 µm) as feeding material.…”

“…This indicated that the C. hislopi grew and reproduced better in condition of low light intensity (probably in darkness), which also explained why the animals always like to hide under layer of soil or vegetation. Although light intensity was not pointed by Yashima et al [16] in their successful culture of C. hislopi the culture tank was covered with thick water ferns (Salvinia auriculata). The presence of thick vegetation had directly reduced the light intensity in their culture tank, which probably became one of the factors that led to the success of their culture.…”