Monhystera parelegantula (De Coninck,1943) was collected from the sediment of the Sluice-dock, a euhaline-polyhaline lagoon near the harbour of Ostend (Belgium). The species was cultivated in large numbers on a bacto-agar medium with bacterial growth. Embryonic growth was studied at 30 °C and 30 promille S. Maximum embryonic length-growth occurs at the vermiform stage. Post-embryonic length-growth, studied at 25 °C and 30 promille S, is a linear function of time and may be expressed as l = 160.46 + 29.55(t-to), where to = time at the beginning of development; t and l = time (d) and length (µm). At 25 °C and 30 promille S, average embryonic development time and generation time are 4 and 9 d respectively. Reproduction under culture conditions is parthenogenetic, but males were sometimes found. Reproduction, feeding and duration of the life cycle are discussed. |
