Hatching of Boeckella hamata (Copepoda: Calanoida) resting eggs from sediments of a tidally influenced lake

Abstract

Boeckella hamata Brehm appears in the plankton of Lake Waihola, New Zealand, a tidally influenced lake, only at times of low salinity. To determine whether B. hamata hatches from resting eggs, allowing it to re‐colonise the lake after periods of higher salinity, sediments were analysed for the presence of eggs and incubated in the laboratory at 15°C. Copepod eggs at a density of 1.3 × 10⁴ eggs m‐² were recorded. Over a 4‐month period, 87 nauplii hatched. Of those identified, 98% were B. hamata and 2% Gladioferens pectinatus Brady. This is the first report of B. hamata resting eggs. We conclude that B. hamata in Lake Waihola can use resting eggs to re‐colonise the plankton when conditions are favourable.

Keywords:

• calanoid copepod
• sediment hatching
• Boeckella hamata
• Gladioferens pectinatus
• re‐colonisation
• resting eggs

Notes

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