Studies on the motility and cryopreservation of rainbow trout (Salmo gairdneri) spermatozoa

The very short duration of vigorous movement (1½ to 7 min) in fresh water and physiological solutions make trout spermatozoa difficult subjects for cryopreservation studies. Solutions consisting of 250 to 280 mmol sucrose and 5 to 12% dimethyl sulphoxide (DMSO) (4 parts) did not activate trout spermatozoa (1 part), but after dilution with fresh water vigorous motility could be fully restored. These sucrose·DMSO solutions were employed in cryopreservation studies. Using straws and a fast freezing - fast thawing procedure, post· thaw dilution with fresh water resulted in 25% - 60% of spero matozoa becoming motile, all with vigorous forward progression. Some existing methods for the cryopreservation of other freshwater fish spermatozoa were repeated on trout without success

Book Reviews

Book Review 1Book Title: Pheromones of Social BeesBook Author: John B. FreeChapman & Hall, 1987. 218 pp.Book Review 2Book Title: Insects - PlantsBook Authors: V. Labeyrie et alDr. W. Junk Publishers, The Hague, 1987. 459 pp.Book Review 3Book Title: The Ecology of Woodland Rodents: Bank voles and wood miceBook Authors: Edited by J.R. Flowerdew, J. Gurnell & J.H.W GippsThe Zoological Society of London. Clarendon Press, Oxford, 1985. 418 pp.Book Review 4Book Title: Visual behavior in salamandersBook Author: Gerhard RothSpringer-Verlag, Berlin, 1987. 301 pp.Book Review 5Book Title: Digestive Physiology and Nutrition of MarsupialsBook Author: Ian D. HumeMonographs on Marsupial Biology. Cambridge University Press, 1982. 256 pp.Book Review 6Book Title: Neurobiology and Behavior of HoneybeesBook Authors: Edited by Randolf Menzel & Alison MercerSpringer-Verlag, 1987.334 pp.Book Review 7Book Title: Ecology and Productivity of an African Wetland SystemBook Author: G.A. EllenbroekDr W. Junk Publishers, Dordrecht, 1987. 267 pagesBook Review 8Book Title: Biological Surveys of Estuaries and Coasts Estuarine and Brackish Water Sciences Association HandbookBook Authors: Edited by J.M. Baker & W.J. WolffCambridge University Press, 1987. 449 pp.Book Review 9Book Title: Caste Differentiation in Social InsectsBook Authors: Edited by J.A.L. Watson, S.M. Okot-Kotber & C.H. NoirotPergamon Press, Oxford, 1985. 399 pp.Book Review 10Book Title: Sistematica, filogenia y biogeografia de la subfamilia Gibbiinae (Coleoptera, Ptinidae)Book Author: Xavier BellésTreballs del Museu de Zoologia, 1985, No.3, Barcelona. 94 pp.Book Review 11Book Title: A Biologist's Advanced MathematicsBook Author: D.R. CaustonAllen & Unwin, London 326 pp.Book Review 12 Book Title: Reproduction in Mammals: 5 Manipulating reproductionBook Authors: Edited by C.R. Austin & R.V. ShortCambridge University Press, London, New York, New Rochelle, Melbourne, Sydney. 235 pp.Book Review 13Book Title: Vertebrate Fetal MembranesBook Author: Harland W. MossmanMacmillan press, 1987. 383 pp.Book Review 14Book Title: Avian Physiology (Fourth edition)Book Author: Edited by P.O. SturkieSpringer-Verlag, New York, 1986. 516 pp

Population fluctuations and breeding of eland <i>Taurotragus oryx </i>in a western Transvaal nature reserve

The history of an eland population on the S A Lombard Nature Reserve in the western Transvaal is described. From a founder population of four eland in 1950 and 1951, the population grew to about 35 animals and was kept at this level through culling and translocation until 1976. During 1976 and 1977 unusual heavy rains were experienced and culling and removals were temporarily suspended. As a result the population increased unchecked and reached a peak of 81 in 1981. When climatic conditions returned to normal this was followed by a population crash in which 66 eland died over a period of three years. Calves are born throughout the year, but the majority of births occur during the period October to December, with a peak in November. The females have a high calving rate (90,9 ) and calf mortality is low (16,7 )

Captive breeding of the white rhinoceros, <i>Ceratotherium simum</i>, and the Cape buffalo, <i>Syncerus caffer</i> : research communication

Breeding records of 40 white rhinoceros and 155 Cape buffalo were analysed. Three rhinoceros cows bred in captivity, themselves conceived for the first time at 84, 87 and 95 months of age, respectively. Rhinoceros cows breed throughout the year. There is no evidence of a relationship between calving interval and month of birth. Calving intervals were normally distributed about the mean of 34 months and there were no significant differences between bulls, cows or sex of calf. There was no difference in the sex ratio of calves born to young cows nor older cows. The male:female ratio of the calves was Younger cows did not have shorter birth intervals. Although captive Cape buffaloes breed throughout the year, there is a preponderance of births in midsummer. There was some evidence that larger cows produce heavier calves and that season of birth may influence birth weight. Male calves weighed 41.20 + 0.68 kg vs 39.00 + 0.73 kg (range 24-60 kg) for female calves but this difference was not significant. Calving intervals were normally distributed about the mean of 395 days and the male:female ratio of the calves was 1:1.2

On the sexual cycle of mature bachelor bontebok rams at the Bontebok National Park, Swellendam

No Abstrac