Growth and development of the copepod Acrocalanus gibber from Chunda Bay, north Queensland

Growth rates of the subtropical copepod, A. gibber, were measured from 9 field and 3 laboratory experiments between April 1992 and November 1994.

Plankton were collected 500 m from the shore in Chunda Bay using a 0.5 m diameter, 280 µm plankton net. Plankton were transferred into a 20 litre bucket filled with water from the bay. In the laboratory, the plankton were concentrated and then sorted under a binocular microspope, 200-400 adult female Acrocalanus gibber were transferred into a 20 cm diameter PVC cylinder with 100 µm mesh covering the bottom. The cylinder was suspended in a bucket containing 20 litres of 37 µm screened bay water, to which excess cultured phytoplankton had been added. Eggs from the females easily isolated from the adults as they passed through the mesh of the cylinder.

Concentrations of eggs and nauplii were kept for field growth experiements in Chunda Bay. Containers were suspended in Chunda Bay in North Queensland and samples removed every 1-2 days. Growth rates and egg production rates were determined. Carbon and nitrogen contents of each of the developmental stages and from the filters (laboratory) and water (field) were recorded.

Date, temperature, chlorophyll a, prosome length, molting rate, and copepod weight were also recorded. The origin of the animals was also recorded: w - wild caught females; e - females produced in experimental incubations.

Field and laboratory studies were carried out to examine the effects of temperature and food supply on growth rates of the copepod, Acrocalanus gibber, a common component of the plankton in subtropical and tropical waters.