摘要:

The methods of collecting data and subsequent computer analysis are described. The characteristic length-weight values (b) of sole populations have been used to illustrate differences between the sexes, seasons and geographical localities. Males and females are similar in length-weight characteristics. However the mean length and weight of males is significantly less than females. Soles are heavier at the same length in summer than in winter. Sole populations are significantly different between trawling grounds. There is a difference in length-weight relationship (b) between the four grounds with the highestbvalue found on the Mud Hole ground in the east. The mean lengths and weights of catches are significantly different between the grounds, with the lowest values found in the east. Possible causes are briefly considered.

ISSN:0035-919X    

DOI:10.1080/00359197409520066

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Two species of sipunculans (Siphonosoma cumanenseandS. rotumanum) were recorded from False Bay, South Africa, expanding their known range. They were collected from 30 to 60 cm below the substrate surface using a diver-operated suction sampler. This note reminds us that our knowledge of the distribution of burrowing marine invertebrates may be very incomplete due to the nature of the collecting gear commonly used.

ISSN:0035-919X    

DOI:10.1080/00359197409520067

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The gonad structure and cycles of sevenPatellaspp. are described. Most spawn once a year.P. cochlear, P. argenvillei, P. barbara, P. granatinaandP. granularisare autumn to winter breeders spawning in May-June.P. oculusspawns in September andP. longicostain October-November. Partial spawning was recorded forP. cochlear, prior to the attainment of maximum maturity. InP. oculusa false spawning of a small percentage of females occurred in May and biannual spawning is possible.

ISSN:0035-919X    

DOI:10.1080/00359197409520068

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

An analysis was undertaken of the growth-rates ofPatella cochlear, P. granatina, P. granularis, P. longicostaandP. oculus.Shell growth is rapid in the first year and then decreases. A negative linear relationship exists between initial length and increment per year. Increases of shell length eventually cease and this may be important in determining longevity. Shell thickness increases throughout life. Body growth is sigmoidal, maximum absolute growth occurring after about a quarter of the life-span is complete.

ISSN:0035-919X    

DOI:10.1080/00359197409520069

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Lembos jassopsisK. H. Barnard 1951 is redescribed and figured, and transferred to the genusPseudomegamphopusMyers. The phylogenetic significance of the relative development of podomeres in corophioidean Amphipoda is discussed.

ISSN:0035-919X    

DOI:10.1080/00359197409520070

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Rectal glands from 8 striped dogfish (Poroderma africanum) were subjected to histochemical examination, incorporating the chloride test and histological staining with Alcian blue-Neutral red, Mallory's stain-Sudan IV and Phosphomolybdic acid orange-Sudan black. The chloride test was carried out on normal fish and ones which had been salt-loaded with interperitoneal NaCl injection. A general radial arrangement of secretory tubules was observed, although in the lower region of the glands the glandular parenchyma was divided into lobules by fibrous septa. The chloride test showed silver granules in the cells of the secretory epithelium, similar in nature to those observed previously (Haywood 1974a) in branchial tissue of the same species.

ISSN:0035-919X    

DOI:10.1080/00359197409520071

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The effects of low concentrations of ammonium nitrate on the fertilization and early development ofChoromytilus meridionalishave been studied in the laboratory at 14°C. Concentrations up to 10 p.p.m. have no significant effect on fertilization, though concentrations as low as 0,5 p.p.m. retard early development. Spontaneous recovery takes place unless the pollutant is repeatedly renewed. At 10 p.p.m. a high proportion of the larvae achieving the veliger stage show abnormal shell growth. At 100 p.p.m. ammonium nitrate there is complete failure to pass beyond the trochophore stage, development tending to terminate at gastrulation. These results contrast with the tolerance of the adults, solutions of 1 000 p.p.m. having no significant effect on either the tendency to shell adduction or the ciliary beat of the gills.

ISSN:0035-919X    

DOI:10.1080/00359197409520072

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The toxicity of ammonium nitrate in natural sea water has been studied with respect to a number of sandy-beach animals, to the rock lobster,Jasus llalandii, and to the isolated heart ofCiona intestinalis.Results are integrated with previous findings on other species.

ISSN:0035-919X    

DOI:10.1080/00359197409520073

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359197409520074

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0035-919X    

DOI:10.1080/00359197409520065

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor