摘要:

Seventeen species of dinoflagellate resting cysts have been recorded for the first time in New Zealand. Isolated from sediments at 93 locations in the Marlborough Sounds, these wereGonyaulax spinifera, G. grindleyi, G. polyedra, G. digitalis, Gonyaulaxsp.,Protoperidinium sub‐inerme, P. pentagonum, P. conicum, P. oblongum, P. leonis, P. cfpunctulatum, P. cf.conicoides, Per‐idinium stellatum, Peridiniumsp.,Scrippsiella tro‐choidea, Polykrikos schwartzii, andDiplopsalissp. here possible their identities were confirmed by hatching experiments yielding live motile cells. Greatest cyst concentrations and species diversity were found in Kenepuru Sound and Tennyson Inlet. These areas may be more likely to harbour toxic species causing paralytic shellfish poisoning (PSP) or diarrhetic shellfish poisoning (DSP) if these were to appear in the future.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516258

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

TorrentfishCheimarrichthys fosteriHaast were collected at 4‐hour intervals over a full day in winter and summer, 1984–85, from the Ashley and Rakaia Rivers in Canterbury, New Zealand, to determine their diel feeding periodicity. Both populations fed, almost exclusively, from dusk to dawn in both seasons, with the quantity of food in their stomachs accumulating to peak levels by early morning. However, Ashley females had significantly less food in their stomachs than did males in summer, the season with a high incidence (91%) of females in spawning condition. Aquatic stages ofDeleatidiumspp. (Ephemeroptera: Leptophle‐biidae) and Chironomidae constituted from 85 to 98% by number and 63 to 80% by dry weight of all foods eaten. Chironomids (small prey) comprised up to 85% of the total foods eaten by number but only 17% by dry weight, whileDeleatidium(large prey) comprised up to 69% of the prey by number and 63% by dry weight. Numerically, chironomids were an important component in the torrentfish diet in both seasons in the Rakaia (71 to 75%), but only so in winter in the Ashley (85%). The reported daily feeding cycle is consistent with observations in a simulated stream, that torrentfish largely remain inactive during the day and come out to feed at night.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516259

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Aerial counts of chinook salmon in tributaries of the Rakaia River, South Island, New Zealand, were made several times in each spawning season from 1973 to 1976, and compared with concurrent ground counts. Smooth curves were fitted to the aerial counts and integrated to provide indices of abundance. Numbers of salmon were estimated by dividing these indices by estimates of the mean residence time offish. For the years 1973, 1974, 1975, and 1976 the numbers of salmon estimated to be in the areas counted were 4595, 5856, 14 222, and 16 702 respectively. Trap counts on one spawning tributary (Glenariffe Stream) made up between 7.6 and 15.5% of the spawning run. Such fluctuation in the proportion of the run in any one tributary may be due to the differing susceptibility of tributaries to flooding.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516260

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Zooplankton and water were sampled from Lakes Taupo and Rotongaio from July 1985 to June 1986. Zooplankton excretion and respiration rates were measured for the copepodBoeck‐ella propinquaand excretion rate also for the zooplankton community. Photosynthetic14C uptake was measured to estimate phytoplankton nitrogen requirements. Highest metabolic rates were found in spring and summer in both lakes. In eutrophic Lake Rotongaio, metabolic rates were closely correlated with temperature. In Taupo, a large oligo‐trophic lake, food supply was also an important variable. The atomic O: N ratio (oxygen consumption: nitrogen excretion) indicated protein utilisation forB. propinquafrom Lake Rotongaio but an alternation between protein and stored lip‐ids for Lake Taupo specimens. The potential contribution of nitrogen regeneration by zooplankton excretion to phytoplankton nutrient requirements was greatest during early stratification in both lakes when zooplankton biomass was greatest (up to 160% of estimated requirements in Lake Rotongaio and 214% in Lake Taupo). Regenerated nitrogen is a major source of nitrogen for Lake Taupo phytoplankton but in Lake Rotongaio other sources are more important.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516261

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The ability of absorbance at 330 nm to predict dissolved organic carbon (DOC) concentration was tested on samples of throughfall, stem‐flow, soil water, and stream water from the Maimai and Larry River catchments, Westland, New Zealand. Predictive ability for the combined samples was poor, but improved when the samples were split into groups of origin. For stream samples, the method gave standard errors of the estimate of 8 to 11% of the mean. Predictive ability was poorer in the other sample groups, especially throughfall and stemflow, presumably because of the occurrence of weakly coloured organic compounds. The slope and intercept of the regressions varied with sample type. The spectrophotometric method is useful where a large number of samples need to be analysed and where calibrations can be developed for specified types of organic‐carbon‐rich waters.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516262

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Samples of berried femaleJasus edwardsii(Hutton) were taken from rock lobster pots fished by commercial fishermen from eight areas around New Zealand, and the number of eggs counted using an electronic egg counter. The size of females ranged from 74 to 157 mm carapace length (CL) and fecundity from 37 499 to 407 032 eggs per female. The fecundity‐size relationship was described by a power function of the form fecundity (f) =a CLb. There were no significant differences between most samples, which resulted in a considerable degree of overlap in the fecundity‐size relationship between areas. The maximum fecundity observed in this study is considerably less than the maximum observed in two previous studies ofJ.edwardsii. Egg loss at Kaikoura between the early and middle stages of the egg‐bearing period was 20%. The fecundity ofJ. edwardsiiis generally less than the fecundity of three other closely relatedJasusspecies (J. lalandii, J. novaehollandiae, andJ. frontalis) at similar sizes.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516263

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

Freeze‐dried or oven‐dried antarctic krill (Euphausia superba) and southern blue whiting (Micromesistius australis) (SBW) were analysed for their proximate and amino acid contents. Each sample was then combined into semi‐purified diets and fed to male weanling rats. The krill and SBW meal provided the sole source of protein in each diet. The true digestibility of the protein of all diets was consistently high (94.0–96.6%). The mean biological value (BV) of the SBW meal was 78.7, similar to that of white fish meal (81.0). The krill meal had significantly lowerBV(mean 65.9), which could be significantly improved on addition of 0.1% DL‐methionine (BV 75.6) or 0.1% cystine (BV72.9).

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516264

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The role of turbidity in scallop mortality was investigated for two size classes ofPecten novaezelandiae(70 ± 2 mm and 20 ± 1 mm shell height), by using the “crawl” velocity of excised pieces of gill tissue as an indicator of the response to suspended silt. The crawl velocity of 3 × 5 mm pieces of gill tissue was measured in six different silt concentrations (0.025, 0.05, 0.1, 0.2, 0.3. 0.5% silt, by dry weight) and two size classes (< 10 μm and 10–30 um) of silt. Results of the study indicate that juvenile (20 mm shell height) scallops may be less tolerant of suspended silt than larger (70 mm shell height) scallops and that both size classes may be less tolerant of fine (< 10 μm) silt/clay sized particles than coarse (10–30 μm) particles. These conclusions are supported in part by data from the mortality of whole 20 mm scallops exposed to two size classes (< 10 μm and 10–30 μm) and three concentrations (0.05, 0.3, 0.6%, by dry weight) of silt. Increasing concentrations and decreasing particle size of the suspended silt resulted in reduced gill piece crawl velocity and an increase in the mortality rate of the whole scallops. These results suggest controls on human‐induced disturbance of bottom sediments, such as bottom trawling and dredging, may benefit any further scallop bed enhancement programmes by the avoidance of deterioration in water quality and mechanical damage to scallop spat.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516265

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A new form of parasitic copepod,Mecaderochondria pilgrimigen. et spec, nov., recovered from the oral cavity of an uranoscopid fish,Kathetostoma giganteum, at Kaikoura, New Zealand, is described. The female of the new genus is characterised by a long neck consisting of the first and second pedigers, and two pairs of modified but uninflated legs with much reduced proto‐pods. The pygmy male has an atrophied antennal tip on the second antenna.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516266

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The new speciesSchackoinella antarcticais described from seafloor sediments in McMurdo Sound and from raised beach samples on Ross Island. This species is a rare calcareous form, averaging 0.1 mm in size, and was found in water 80 to 620 m deep in McMurdo Sound. No live specimens have been recovered. Forms belonging to this genus have also been found in India, Western Australia, Austria, and possibly Poland.

ISSN:0028-8330    

DOI:10.1080/00288330.1987.9516267

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor