Sperm characterization of the Amazonian freshwater cururu stingrayPotamotrygon wallacei(Potamotryogonidae): basic knowledge for reproduction and conservation plans

Abstract

SummaryThis study aimed to describe the morphology and sperm quality of free-living adult males of cururu stingray Potamotrygon wallacei, endemic from the Rio Negro basin, Brazilian Amazon. The sperm was collected in loco from the seminal vesicle region and fixed in buffered saline formaldehyde solution for further evaluation of morphometry, sperm plasma membrane integrity and sperm concentration. The spermatozoa presented a total length of 138.25 ± 1.82 μm with a helical shape and a long head. A high percentage of cells with intact membrane (98 ± 2%) and normal spermatozoa (92 ± 1%) were observed. The cell concentration was 0.34 ± 0.05 × 1010 spermatozoa/ml of semen. These observations are unprecedented for potamotrygonid species and will serve as a basis for future management and conservation strategies.

Characterization of short‐term storage of the semen ofTrachelyopterus galeatus(Siluriformes: Auchenipteridae) incorporating dimethylsulphoxide (dmso) to the diluent

“…Although the reproductive capacity of T . galeatus in captivity is unknown, information about sperm parameters is indispensable for in vitro handling and conservation of genetic material, which is an important technology for preservation and improved production of wild species (Dzyuba et al, 2019; Morales‐Gamba et al, 2019).…”

Unraveling Metabolite Provisioning to Offspring Through Parental Fluids: A Case Study of the Brazilian Guitarfish, Pseudobatos horkelii

“…Although parental input to embryo nutrition is well-established through the detailed description of vitellogenesis for various elasmobranchs ( Ballantyne, 1997 ; Lucifora et al, 2002 ), several knowledge gaps still remain especially for other parental matrices, including uterine fluid in the case of viviparous species (i.e., lecithotrophic) and uterine milk in the case of matrotrophic viviparous species (i.e., histotrophy). In the case of males, knowledge is even more incipient, as detailed semen descriptions are often restricted to sperm morphology, mobility, and spermatozoa concentrations ( Girard et al, 2000 ; Dzyuba et al, 2019 ; Morales-Gamba et al, 2019 ; Rowley et al, 2019 ). As spermatozoa rely on external signaling to activate motility, it is reasonable to infer that some energy source may be available in the seminal fluid to complement the energy expenditure necessary during sperm transfer and egg fertilization.…”

Reproductive Anatomy of Chondrichthyans: Notes on Specimen Handling and Sperm Extraction. I. Rays and Skates

“…This technique has been receiving increasing attention, but to ensure the success of this technique, a reliable supply of sperm is required, especially in the case of endangered species [18][19][20][21]. Sperm can be obtained from dead or live animals, and although there has been success in obtaining sperm from several batoids [18,[22][23][24], the procedures of extraction may vary between the different species. Cannulation and abdominal pressure are the traditional procedures used [21], but with these techniques, the location and morphology of the species-specific reproductive structures (for example seminal vesicles and urogenital papilla) need to be considered.…”