http://aerg.canberra.edu.au/library/sex_general/2002_Devlin_Nagahama_sex_determination_in_fish_review.pdf

Sex determination and sex differentiation in fish: an overview of genetic, physiological, and environmental influences

Physiological changes in fish from stress in aquaculture with emphasis on the response and effects of corticosteroids

It is becoming evident that an increasing number of widely used industrial and agricultural chemicals are estrogenic. The biodegradation products of a major group of nonionic surfactants, the alkylphenol polyethoxylates, are one such group. Some of these chemicals are widespread aquatic pollutants, and bioconcentrate in aquatic biota. Exposure of male rainbow trout (Oncorhynchus mykiss) to four different alkylphenolic chemicals caused synthesis of vitellogenin, a process normally dependent on endogenous estrogens, and a concomitant inhibition of testicular growth. The magnitude of these estrogenic effects was dependent on the estrogenic potency of the chemical, the stage of reproductive development of the fish, and the concentration of the chemical in the water. These results support the contention that exposure of wildlife to environmentally persistent estrogenic chemicals can result in deleterious reproductive consequences.

Inhibition of testicular growth in rainbow trout (Oncorhynchus mykiss) exposed to estrogenic alkylphenolic chemicals

Preface. Selected Atomic Weights. Customary Metric Conversion Factors. 1. Water Quality and Aquaculture: Preliminary Considerations. 2. Ecology of Aquaculture Ponds. 3. Water Quality Requirements. 4. Water Use. 5. Liming. 6. Fertilization. 7. Aeration. 8. Water Circulation. 9. Turbidity and Appearance of Water. 10. Aquatic Weed Control. 11. Off-Flavors and Harmful Algae. 12. Pollution. 13. Chemical, Physical, and Biological Treatments. 14. Waste Management. 15. Measurement of Water Quality. 16. Sustainability and Environmental Issues. References. Index.

Pond aquaculture water quality management

Spermatogenesis in fish.

https://hal.archives-ouvertes.fr/hal-01600956/document

Rhythms of reproduction in teleost fish

The effects of daily administration of LHRH analogue (D-Ala8-desGly10) LHRH ethylamide in NaCl or propylene glycol for five days was studied on spermiation, plasma gonadotropin and 11-ketotestosterone levels. Daily injection of 10 μg/kg body weight of LHRH analogue in 0.7% NaCl increased the volume of collectable milt, the number of spermatozoa, and serum gonadotropin and 11-ketotestosterone levels. Daily injection of 1 μg/kg in NaCl or 1 μg/kg and 10 μg/kg in propylene glycol did not stimulate these respnses. Theses results indicate that LHRH analogue can stimulate the secretion of GtH from pituitary gland which in turn stimulates androgen secretion and the spermiation in the testis.

Stimulation of spermiation by LHRH analogue in carp.

/pdf/les-cellules-de-sertoli-des-poissons-teleosteens-i-etude-4jg1elbolu.pdf

Les cellules de sertoli des poissons téléostéens. i. — étude ultrastructurale

During a 9-month period (corresponding to a sexual cycle), the adult male tench, Tinca tinca, was kept in fish farm ponds receiving heated water from a power plant. In 1974, the males were submitted to three different temperature regimes: group I: ambiant temperature; group II: ambiant temperature +3 degrees C; group III: ambiant temperature + 6 degrees C. The experiment was repeated in 1975, but only using groups I and III. The reproductive cycle and thermal treatment were studied from a quantitative analysis of spermatogenesis, the duration of the spawning cycle and radioimmunoassay (RIA) measurement of gonadotropin (GTH) in plasma and pituitary, using a carp RIA system turned out to be sensitive enough to assay tench GTH, which was expressed in a c-GTH equivalent. Spermatogenesis in the tench was a discontinuous process, starting in the spring and finishing in the summer. It began earlier in heated water in which the spawning period was also considerably longer (3 months in group III against 1 month in group I). At the beginning of spermatogenesis, pituitary and plasma GTH was low, but rose rapidly when spermatogenesis was initiated (appearance of type B spermatogonial cysts and meiosis). The highest GTH levels in the blood were recorded during the spawning period, with important fluctuations probably due to discharges from the pituitary.

/pdf/temperature-and-reproduction-in-tench-effect-of-a-rise-in-21lsw4unk3.pdf

Temperature and reproduction in tench: effect of a rise in the annual temperature regime on gonadotropin level, gametogenesis and spawning. I. The male.

Morphological investigations on the changes in flagellar beating was carried out on native (taken from the milt) and thawed sperm of the Siberian sturgeon Acipenser baerii (Brandt). Immediately after activation, the pattern of flagellar wave formation and distribution was the same in native and thawed sperm but, after 27–42 s, depending on the samples, the thawed flagella showed asymmetric and poorly developed waves. The swimming trajectories recorded during 1-s exposure were much shorter in thawed than in native sperm after 26–28 s motility. In native sperm, the flagella remained in the same axis as the head during the entire motility course, while the head of thawed sperm showed a right angle after 47 s. It is concluded that the freezing/thawing procedure induces some alteration in the dynamics of flagellar beating in many sperm, but these sperm still show progressive displacement. Therefore, the change in morphology of the flagellum during motion is a parameter that should be taken into account in the evaluation of the impact of various treatments on sperm motility.

Roland Billard

Papers

Rhythms of reproduction in teleost fish

Stimulation of spermiation by LHRH analogue in carp.

Les cellules de sertoli des poissons téléostéens. i. — étude ultrastructurale

Temperature and reproduction in tench: effect of a rise in the annual temperature regime on gonadotropin level, gametogenesis and spawning. I. The male.

Changes in the flagellum morphology of intact and frozen/thawed Siberian sturgeon Acipenser baerii (Brandt) sperm during motility.