Growth of red gurnard (Teleostei: Triglidae) from Pegasus bay,Canterbury, New Zealand

Growth of the red gurnard, Chelidonichthys kumu (Lesson and Garnot), from Pegasus Bay, Canterbury, was measured during 1966–67. Otoliths were used as an indicator of fish growth; mean length‐at‐age data were obtained from back‐calculated fish lengths at the time of formation of successive annual rings in the otoliths. Growth in length was found to be adequately expressed by the von Bertalanffy growth equation :

l_t = 52.0 [1 ‐ e‐^{0.406 (t‐o.291)}]

(where l_t is the fork length in cm at age t). The length: weight relationship was:

w = 78.56 × 10^‐4 l ^3.072

(where w is the weight in grams). From this relationship, growth in weight was described by the equation:

w_t = 1469 [1 ‐ e‐0.406 (t‐0.291)]³.     

Weed preference and growth of young grass carp in New Zealand

In each of eight 5‐day pond experiments carried out at intervals over a year, 0+ to 1 +‐year‐old grass carp, Ctenopharyngodon idella Val., were offered a choice of at least 10 species of water weeds from the Rotorua area. Water temperature was measured each day. Food selectivity decreased with increasing temperature and size of fish, but preference for the weeds did not change. At summer temperatures the fish ate much weed and grew at about 4g/fish/day, but in winter little food was taken and growth was slow.     

Introduction,preliminary handling,and diseases of grass carp in New Zealand

Fry of grass carp, Ctenopharyngodon idella (Val.), were air‐freighted from Hong Kong to New Zealand in October 1971. The fish were at first kept in tanks with a recirculating water supply, where they soon showed symptoms of parasitic infestation and suffered heavy mortality.

Attempts were made to remove parasites with chemotherapeutic treatment. Tripartiella sp., Dactylogyrus ctenopharyngodonis, and Gyrodactylus clenopharyngodontis were eliminated by prolonged bathing of the infected fish with quinine. Chemical treatment failed to eliminate Ichthyophthirius mullifiliis from the body surface and the gills, but the rate of spontaneous recovery of the fish from this disease was accelerated by keeping them in clean, running water. Experiments to remove the cestode Bothriocephalus gowkongensis from the intestine of the fish with tetravalent tin compounds and to control the intermediate host (Cyclops) in the water resulted in the eradiction of the cestode.

When parasitic infestations had been brought under control the fish were transferred to outdoor ponds, where they began to feed on aquatic and terrestrial vegetation and rapidly increased in size.     

Halosaurus pectoralis McCulloch (Pisces: Halosauridae) in the New Zealand region (note)

Halosaurus pectoralis McCulloch is recorded from off Gisborne, New Zealand, and from south‐east of Lord Howe Island, thus adding a second species of the order Heteromi to the New Zealand fauna.     

Developmental energetics of the southern pigfish (Teleostei: Congiopodidae)

The embryonic wet weight, dry weight, yolk volume, energy content, and oxygen consumption of the southern pigfish Congiopodus leucopaecilus (Richardson, 1846) were followed from fertilisation to yolk sac absorption, at 11.5°c and salinity of 34.5%6. Measurements of yolk energy and catabolic energy changes did not show any evidence of an energy deficit before the onset of feeding capability.     

Hydrolytic enzymes of the paua Haliotis iris,a marine gastropod (note).

Extracts of the viscera of Haliotis iris (Martyn, 1784) were shown to hydrolyse 2‐hydroxy‐5‐nitrophenyl sulphate at pH 5.5, and the p‐nitrophenyl derivatives of α‐ and β‐D‐galactose, α‐ and β‐D‐mannose, α‐L‐lucose, β‐D‐glucuronic acid, β‐N‐acetyl glucosamine and phosphate at pH 4.0 and 5.5: p‐nitrophenyl‐β‐L‐fucose was not hydrolysed.     

Reduction of a population of Canterbury mudfish,Neochanna burrowsius (Galaxiidae), by drovight

A population of Canterbury mudfish Neochanna burrowsius (Phillipps), estimated to exceed 3000 adults in July‐December 1975, and its habitat at Clearwell in mid Canterbury, are described. A 7 month drought nearly extinguished the population; this and the subsequent return migration (in August 1976) of survivors from a stockwater race are recorded.     

Common bivalve larvae from New Zealand: Leptonacea

The late stage larvae of three erycinid bivalves (Mollusca: Pelecypoda: Leptonacea) taken from the brood chamber of the adult are described (Kellia cycladiformis, Lasaea rubra hinemoa, and L. maoria), and the provisionally identified late stage larva of the erycinid Arthritica bijurca taken from the plankton is described. Also, the D‐shaped larvae of the erycinid bivalves Kellia cycladiformis, Borniola reniformis, Arlhritica crassijormis, and A. bifurca taken from the parent brood chamber are described. The seasonal occurrence of each late stage larva in the plankton at the Bay of Islands (35° 15'S, 174° 10'E), Wellington Harbour (41° 16'S, 174° 51'E), and Raumati Beach (40° 56'S, 174° 58'E), New Zealand is described. Aspects of the reproductive cycles of Lasaea rubra hinemoa and Arthritica bifurca are presented.     

Spawning of the frostfish,Lepidopus caudatus (Pisces: Trichiuridae), in New Zealand waters

Frostfish spawning, as indicated by the presence of planktonic eggs, was observed mainly in north‐eastern, but also in south‐western, New Zealand waters in spring to autumn. Spawning takes place in the afternoon in outer shelf waters 50–200 m deep, with surface temperatures and salinities between 17.5 and 22.0°C and 35.3 and 35.6‰ respectively. Egg and oil droplet diameters ranged from 1.65 to 1.75 mm and 0.40 to 0.43 mm respectively.     

Copper,chromium, and lead in Manukau Harbour sediments

A limited survey was undertaken to determine the concentrations of copper, lead, and chromium in sediments of the upper Manukau Harbour, New Zealand. The concentrations of copper and chromium (33–70 and 70–107 μg g^‐1 respectively) were of the same order of magnitude as those reported for other New Zealand harbours. However, lead concentrations (98–247 μg g^‐1) were higher than those found for the other harbours. This may be a consequence of higher traffic densities in the surrounding area.