Benefits of hormone treatment of both sexes in semi-artificial reproduction of pikeperch (Sander lucioperca L.)

Abstract

Propagation of pikeperch Sander lucioperca by semi-artificial management was investigated using hormonal induction to better understand the effect of hormonal treatment of both sexes. Fourteen pairs of pikeperch brood fish were divided into two groups (seven pairs in each group). Seven females in Group A and both sexes in Group B were hormonally injected with 500 IU of hCG per kg. Each pair of brood fish was held separately in a 300-l circular tank with an added spawning material on the bottom. Brood fish were removed from the tanks on the day after spawning; three-hundred randomly selected eggs were removed from the spawning nests and transferred to 250 ml plastic incubators. Sperm samples were collected from males in individual 1-ml syringes. Significant differences in fertilization rate (Group A 59.5%, Group B 80.4%), hatching rate (Group A 51.2%, Group B 71.6%), and number of larvae produced per female (Group A 49 429, Group B 122 000) were observed. Differences were attributable to sperm quality, primarily volume (Group A 0.16 ml, Group B 0.64 ml), and duration of spermatozoa motility (Group A 59.5 s, Group B 97.7 s). Hormone treatment of both sexes is beneficial for pikeperch semi-artificial reproduction by inducing ovulation and improving milt production and spermatozoa quality, fertilization and hatching rate, all contributing to a higher number of produced larvae.

Improvements on Live Feed Enrichments for Pikeperch (Sander lucioperca) Larval Culture

“…Spawning and fertilized egg production were obtained from pond-cultured pikeperch broodstock [29,30] (TL = 517 ± 35 mm and W = 1215 ± 200 g), held at the same facility under controlled conditions [31] in RAS. Used broodstock was regularly spawned since 2017, Final oocyte and sperm maturation was performed under spawned 15:9 h light:darkness regime with a light intensity of 100 lux, water temperature of 15 ± 0.5 • C [6,31,32], and synchronized with a dose of the intramuscular hormonal injection Human Chorionic Gonadotropin (hCG; Chorulon, Intervet International B.V.) at 500 IU.kg −1 , as previously cited by Křištan [33] and Blecha [31]. All broodstock were anesthetized with clove oil (Dr. Kulich Pharma Ltd., Hradec Králové, Czech Republic) at a concentration 30 mgL −1 [34], before manipulation.…”

“…This fresh and brackish water species, commonly found in Central, Eastern, and Northern Europe, [2], is highly demanded by the gastronomic industry and the recreational angling community [3]. Most of pikeperch production currently comes from wild fisheries, but production in Recirculating Aquaculture Systems (RAS) is increasing (FAO, 2013), due to its high market value and fast growth rate in RAS [4][5][6][7].…”

The substrate selection and spawning behaviour of pikeperch Sander lucioperca L. broodstock under pond conditions

“…Ninety-six hours after initiation of hatching, when hatching was complete, nests were removed from the tanks, and larvae were concentrated in a 10 L volume in a 20-L tank for counting (Blecha, Samarin, Kristan, & Policar, 2016). The hatching rate (%) was investigated from 100 randomly selected eggs which were separated from each nest immediately after moving to the RAS and divided equally between two 250-ml plastic jars.…”

Use of Lactic Acid Bacteria During Pikeperch (Sander lucioperca) Larval Rearing

“…Spawning and fertilized egg production was from pond-cultured pikeperch broodstock [25,26] (TL = 517 ± 35 mm and W = 1215 ± 200 g) held at the same facility under controlled conditions [27] in RAS. Final oocyte and sperm maturation were performed under a 15 h:9 h light/darkness regime with a light intensity of 100 lux, and a water temperature of 15 ± 0.5 • C [27][28][29]. It was synchronized with an intramuscular hormonal injection of 500 IU·kg −1 of Human Chorionic Gonadotropin (hCG; Chorulon, Intervet International B.V. Ljubljana, Slovenia), as previously done by Křištan [30] and Blecha [28].…”

“…Final oocyte and sperm maturation were performed under a 15 h:9 h light/darkness regime with a light intensity of 100 lux, and a water temperature of 15 ± 0.5 • C [27][28][29]. It was synchronized with an intramuscular hormonal injection of 500 IU·kg −1 of Human Chorionic Gonadotropin (hCG; Chorulon, Intervet International B.V. Ljubljana, Slovenia), as previously done by Křištan [30] and Blecha [28]. All broodstock were anesthetized with clove oil (Dr. Kulich Pharma Ltd., Hradec Králové, Czech Republic) at a concentration of 30 mgL −1 [31] before manipulation.…”