A first observation of spermatogenesis in mature male scalloped hammerheads (Sphyrna lewini) from Zinkwazi, KwaZulu-Natal, South Africa
Tóm tắt
Sharks are not only threatened, but also have a low fecundity as they are being overfished. The shark family, Sphyrnidae, consists of nine species of which three are found in South African oceans. One of the three Sphyrnidae species, the scalloped hammerhead (Sphyrna lewini) are the most common, but their biology and mode of reproduction are not extensively studied in terms of their reproductive biology. The aim of this study was to describe the germ cell development in the testes of sexually mature male scalloped hammerheads. Three individual male S. lewini were caught at Zinkwazi, KwaZulu-Natal, South Africa. The sharks and their reproductive organs were weighed and measured to collect the biometric data for the condition factor and the gonado-somatic index. Following standard necropsy, the testes were fixed in Bouin’s solution and processed for histological assessment. The histological assessment revealed that the testes of S. lewini consist of seminiferous tubules which form part of a larger lobular structure with germ cells in different stages of development, from spermatogonia to mature spermatozoa. Seven stages of development were identified during the process of spermatogenesis, similar to what has been described for elasmobranchs. In conclusion, this study provides evidence that the testes of S. lewini are diametrical and polyspermatocystic and conforms to the testes structure of elasmobranch males.
Tài liệu tham khảo
Adams SM, Brown AM, Goede RW (1993) A quantitative health assessment index for rapid evolution of fish condition in the field. Trans Am Fish Soc 1(122):63–73
Bass AJ, D’aubrey JD, Kistnasamy N (1975) Sharks of the east coast of southern Africa. 3. The families Carcharhinidae (excluding Mustelus and Carcharhinus) and Sphyrnidae. Investl Rep oceanogr Res Inst S Afr (38):100
Baum J, Clarke S, Domingo A, Ducrocq M, Lamónaca AF, Gaibor N, Graham R, Jorgensen S, Kotas JE, Medina E, Martinez-Ortiz J, Monzini Taccone di Sitizano J, Morales MR, Navarro SS, Pérez-Jiménez JC, Ruiz C, Smith W, Valenti SV and Vooren CM (2009) Sphyrna lewini The IUCN Red List of threatened species 2009
Bejarano-Álvarez M, Galván-Magaña F, Ochoa-Báez RI (2010) Reproductive biology of the scalloped hammerhead shark Sphyrna lewini (Chondrichthyes: Sphyrnidae) off south-west Mexico. Aqua Inter J Ichthyol 17:1–15
Branch G, Branch M, Griffiths C, Beckley L, King D (2017) Two oceans: a guide to marine life of southern Africa 4th edition. Struik Nature Publishers, South Africa Page: 258
Cardeñosa D (2019) Genetic identification of threatened shark species in pet food and beauty care. Conserv Genet 20:1383–1387
Carlander KD (1969) Handbook of freshwater fishery biology. Volume 1. Iowa State University Press. pp. 782
Chapman DD, Shivji MS, Louis E, Sommer J, Fletcher H, Prodöhl PA (2007) Virgin birth in a hammerhead shark. Biol Lett 3(4):425–427
Chieffi G (1962) Endocrine aspects of reproduction of elasmobranch fishes. Gen Comp Endocrinol 1:275–285
Cliff G, Dudley SFJ (1992) Protection against shark attack in South Africa, 1952-90. Mar Freshw Res 43:263–272
Cliff G, Dudley SFJ, Davis B (1990) Sharks caught in the protective gill nets off Natal, South Africa. 3. The shortfin mako shark Isurus oxyrinchus (Rafinesque). S Afr J Mar Sci 9:115–126
Compagno LJV (1984) F.A.O. species catalogue. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. (1) Hexanchiformes to Lamniformes. FAO Fish Synop 125:1249
Compagno LJV, Dando M and Fowler S (2005) Princeton field guide: sharks of the world. Princeton University Press Page: 323
Conrath CL (2005) Reproductive biology. Virginia Institute of Marine Science Books and Book Chapters 26
Das Neves J, Barnhoorn IEJ, Wagenaar GM (2018) The effects of environmentally relevant concentrations of aldrin and methoxychlor on the testes and sperm of male Clarias gariepinus (Burchell, 1822) after short-term exposure. Fish Physiol Biochem 44(6):1421–1434
De Bruyn PA, Dudley SFJ, Cliff G, Smale MJ (2005) Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. The scalloped hammerhead shark Sphyrna lewini (Griffith and Smith). Afr J Mar Sci 27:517–528
Do Rêgo GM, Fitzpatrick JL, Hazin FHV, Araujo MLG, Gomes Barros ME, Neto JE (2016) Comparison of the morphology and histomorphometry of spermatogenic cyst of three shark’s species with diametric testes. Anat Rec 6(299):759–768
Dudley SFJ, Cliff G (1993) Sharks caught in the protective gill nets off Natal, South Africa. The blacktip shark Carcharhinus limbatus (Valenciennes). S Afr J Mar Sci 13:237–254
Dudley SFJ, Simpfendorfer CA (2006) Population status of 14 shark species caught in the protective gillnets off KwaZulu-Natal beaches, South Africa, 1978–2003. Mar Freshw Res 2(57):225–240
Dudley SFJ, Haestier RC, Cox KR, Murray M (1998) Shark control: experimental fishing with baited drumlines. Mar Freshw Res 49(7):653–666
Dulvy NK, Fowler SL, Musick JA, Cavanagh RD, Kyne PM, Harrison LR, Carlson JK, Davidson LN, Fordham SV, Francis MP, Pollock CM, Simpfendorfer CA, Burgess GH, Carpenter KE, Compagno LJ, Ebert DA, Gibson C, Heupel MR, Livingstone SR, Sanciangco JC, Stevens JD, Valenti S, White WT (2014) Extinction risk and conservation of the world’s sharks and rays. Elife 3:e00590
Girard M, Rivalan P, Sinquin G (2000) Testis and sperm morphology in two deep water squaloid sharks, Centroscymnus coelolepis and Centrophorus squamosus. J Fish Biol 57:1575–1589
Grier HJ (1992) Chordate testis: the extracellular matrix hypothesis. J Exp Zool 261:151–160
Griffen E, Miller KL, Freitas B, Hirshfield M (2008) Predator as prey: why healthy oceans need sharks. Oceana
Hamlett WC (2005) Reproductive biology and phylogeny of Chondrichthyans: sharks, batoids and chimaeras. Science Publishers Inc, New Hampshire
Hazin F, Fischer A, Broadhurst M (2001) Aspects of reproductive biology of the scalloped hammerhead shark Sphyrna lewini, off northeastern Brazil. Environ Biol Fish 61:151–159
Humason GL (1979) Animal tissue techniques. New York: Freeman and Company. (4): 60
International Union for Conservation of Nature (ICUN) (2014) A quarter of sharks and ray threatened with extinction
Jensen CF, Natanson LJ, Pratt HL, Kohler N, Campana SE (2002) The reproductive biology of the porbeagle shark (Lamna nasus) in the western North Atlantic Ocean. Fish Bull 100(4):727–738
Logan RK, White C, Winkler C, Jorgenson S (2018) The evaluation of body condition and morphometric relationships within southern California juvenile white sharks Carcharodon carcharias. J Fish Biol 93(5):842–849
McClusky LM (2018) Multiple sources for Sertoli cells and two Sertoli phenotypes in the adult elasmobranch testis: insight from two species belonging to different orders. Anat Rec 301(11):1944–1954
McClusky LM, Sulikowski J (2014) The epigonal organ and mature pole of the testis in the recreationally fished blue shark (Prionace glauca): histochemico-functional correlates. J Anat 225(2014):614–624
McComb DM, Tricas TC, Kajiura SM (2009) Enhanced visual fields in hammerhead sharks. J Exp Biol 212:4010–4018
Parsons GR, Grier HJ (1992) Seasonal changes in shark testicular structure and spermatogenesis. J Exp Zool 261:173–184
Pratt HL (1988) Elasmobranch gonad structure: a description and a survey. Copeia 3:719–729
Pratt HL, Tanaka S (1994) Sperm storage in male elasmobranchs: a description and survey. J Morphol 219:297–308
Stehmann MF (2002) Proposal of a maturity stages scale for oviparous and 1679 viviparous cartilaginous fishes (Pisces, Chondrichthyans). Arch Fish Mar Res 5:23–48
Stevens JD, Lyle JM (1989) Biology of three hammerhead sharks (Eusphyra blochii, Sphyrna mokarran and S. lewini) from northern Australia. Aust J Mar Freshwat Res 40(2):129–146
Van Dyk JC, Pieterse GM (2008) Histo-morphological study of the testis of the sharptooth catfish (Clarias gariepinus) as reference for future toxicological assessments. J Appl Ichthyol 24(4):415–422