Seminal and spermatic characteristics of fresh semen and the effects of sperm cooling in Steindachneridion melanodermatum (Garavello, 2005)

Abstract

This study describes the seminal and spermatic characteristics of fresh semen of Steindachneridion melanodermatum and investigates the effects of dilution, temperature, and storage period on its spermatic parameters. Sperm samples were collected from nine hormonally-induced males. The following parameters in fresh sperm were analyzed: seminal plasma osmolality (OSM), seminal pH, sperm motility (MOT), sperm velocity (SV) (including sperm curvilinear velocity (VCL), sperm straight-line velocity (VSL), and sperm average path velocity (VAP)), total time of sperm motility (TEMP), sperm concentration (CONC), and index of sperm normality (NORM). Sperm samples from each male were diluted in a solution containing 5% fructose and 5% powdered milk, and stored at 10°C and 25°C. The same was carried out for sperm samples not subjected to dilution. From these samples, MOT, VCL, VSL, VAP, SV, and TEMP were measured after 0 h, 5 h, 9 h, 18 h, 27 h, 36 h, 45 h, and 54 h. Males released 11.74 ± 5.38 mL of sperm, with an osmolality of 258.78 ± 29.36 mOsm.kg -1 and pH of 7.11 ± 0.31. The sperm presented a MOT of 99.86 ± 0.31% at a concentration of 1.03 × 10 10 ± 3.65 × 10 9 spermatozoa. The results indicate that sperm motility, sperm velocity, and total time of sperm activation were affected by dilution, storage temperature, and storage period (p < 0.05). Procedures for semen storage should be performed with undiluted sperm cooled at 10°C, or kept undiluted at 25°C for up to 27 h. Key words: CASA, endemic, sperm characterization, sperm motility, sperm storage, sperm velocity ResumoO objetivo deste estudo foi descrever os parâmetros seminais e espermáticos no sêmen fresco do Steindachneridion melanodermatum e os efeitos da diluição, da temperatura e do tempo de estocagem do sêmen sobre os parâmetros espermáticos. Foi coletado o sêmen de nove machos, induzidos hormonalmente. No sêmen fresco foram avaliados os parâmetros: osmolaridade do plasma seminal (OSM), pH seminal (pH), motilidade (MOT) e velocidades espermáticas (VCL, VLR, VMD, VE),

Quantitative and qualitative variables of semen from surubim do Iguaçu, Steindachneridion melanodermatum Garavello, 2005 (Siluriformes: Pimelodidae)

“…The analysis of motility duration of S. melanodermatum revealed similar results with activation using tank water (154.4±72.6 seconds) and distilled water (149.0±77.5 seconds) (Table 1). These values were higher than those obtained by Marcos et al (2015) for S. melanodermatum, which found an average of 79.31 seconds, most probably due to the higher dilution we used in the present study.…”

“…Specimens maintained in captivity with adequate feed and water provide good results (Table 1). Marcos et al (2015), observed for this species in October higher volumes (mean of 11.7 mL) when compared with the present experiment. Such a difference may arise because January those fish may be at the end of the spawning season, as observed in other Neotropical species which concentrates the reproduction during the October to December (Godoy, 1975;Vazzoler, 1996;Agostinho et al, 2004).…”

“…The mean concentration of spermatozoa of S. melanodermatum was 5.423 ± 2.155 x 10 10 spermatozoa/mL (Table 1). Marcos et al (2015), observed lower sperm concentration (1.03 x 10 10 spermatozoids/mL) for this species, possibly due to the higher volume of semen obtained by these authors. Luz et al (2001) describe concentrations between 1.95 and 12.015 x 10 10 spermatozoa/mL for S. scriptum.…”

“…Ludwig et al (2005) presented an adapted protocol for induced reproduction of S. melanodermatum. Marcos et al (2015), report some reproductive characteristics for S. melanodermatum species, however, there are few studies of this catfish and its semen features.…”

“…Semen quality and other factors such as the water used for gamete activation are important to optimize in vitro fertilization. Studies evaluating the semen characteristics of South American fishes, such as Steindachneridion scripta (Luz et al, 2001), Leporinus elongatus (Streit Junior et al, 2008), Colossoma macropomum (Maria et al, 2012), Brycon orbignyanus (Galo et al, 2011), Pseudoplatystoma reticulatum (Streit Junior et al, 2012), Leiarius marmoratus (Galo et al, 2014) and S. melanodermatum (Marcos et al, 2015) have been conducted in recent years to determinate the actual potential of each species in fish farming activities.…”