Chilled and post-thaw storage of sperm in different goldfish types.

The effective storage time of sperm after stripping (for 48 hr in 6-hr intervals) and after thawing (for 6 hr in 2-hr intervals) in Black moor, Oranda and Calico goldfish types was investigated. Variations in sperm density were also measured in all lines. The efficiency of a sperm cryopreservation method formerly developed for common carp was recorded in all three goldfish lines. Motility parameters ((pMOT, %), curvilinear velocity (VCL, µm/s) and straightness (STR, %)) of Black moor sperm did not decrease significantly during 48 hr of storage. A significant reduction in the Oranda type compared to the fresh control was observed in pMOT after 42 (23 ± 2%) and VCL after 36 (94 ± 12 µm/s) hours (pMOT 84 ± 5%, VCL 150 ± 11 µm/s). In the Calico type, pMOT decreased significantly already after 18 (42 ± 26%) and VCL after 6 (105 ± 8 µm/s) hours (fresh: pMOT 92 ± 5%, VCL 151 ± 6 µm/s). A high pMOT immediately following thawing was measured in Oranda (46 ± 12%) and Calico (55 ± 15%) types, whereas a reduced pMOT was recorded in Black moor (24 ± 19%). In Calico, pMOT showed a significant reduction after 6 hr (19 ± 11%) in comparison with the initial value, with no changes observed in VCL and STR. None of the parameters changed in the Black moor and Oranda types. Evidence was found that different goldfish lines have different sperm quality and characteristics. Further studies can investigate the possible effects of chilled and post-thaw storage on the fertilizing capacity of sperm in the Black moor, Oranda and Calico goldfish types.

Steroid profiles in cultured female jundiá, the Siluridae Rhamdia quelen (Quoy and Gaimard, Pisces Teleostei), during the first reproductive cycle.

The jundiá Rhamdia quelen (Quoy and Gaimard) is a teleost species from the Siluridae family and is an important species for aquaculture in temperate and subtropical climates. Gonad and blood tissue samples were taken from cultured jundiá females between 1998 and 1999. Plasma concentrations of 17beta-estradiol (E(2)), testosterone (T), 11-ketotestosterone (11-KT), 17-hydroxy-4-pregnene-3,20-dione (17-P), 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P), and 17,20beta,21-trihydroxy-4-pregnen-3-one (20beta-S) were measured by radioimmunoassay and potential correlations with the stage of oogenesis and sexual maturation examined. During the experimental period two spawning episodes were observed. Plasma concentrations of E(2) increased progressively during oocyte development, simultaneously with the appearance of yolk vesicles and increasing amounts of deposited yolk. In female jundiá, the T peak occurred in October and was coincident with the peak in gonadosomatic index. Two distinct peaks of progestogens were detected, corresponding to the two spawning episodes, suggesting that one or more of these steroids might act as the "maturational-inducing steroid" in jundiá. Unusually large amounts of 11-KT were also measured in the plasma of mature jundiá females. The identity of 11-KT was confirmed by thin-layer chromatography. Although the profiles of the other steroids are compatible with the roles proposed for the action of these hormones in other teleosts, the role of 11-KT, normally found only in males, is unknown.