Histological Study of the Male Internal Genital Tract of Dwarf Caiman (Paleosuchus palpebrosus Cuvier, 1807)

Updata:01-01-1970

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By:Teresinha Inês Assumpção, Adrielly Julien Silva Lopes, Lilja Fromme, André Luíz Quagliatto Santos

DOI: https://doi.org/10.30564/jzr.v3i3.3448

Abstract:
Brazil has six species of crocodiles belonging to the subfamily Caimaninae,
one of them being Paleosuchus palpebrosus (Cuvier, 1807) (dwarf caiman).
It is considered one of the smallest crocodilian species, and is sensitive to
environmental changes. The anatomical and histological descriptions of
the reproductive tract of reptiles are scarce, so it is important to study the
morphology of the genital tract of caimans for a better understanding of the
reproduction of these species. We performed the histological analysis of the
testis, epididymis, and deferent duct of the dwarf caiman Paleosuchus pal
pebrosus. Structures of the genital tract were collected from euthanized an
imals. Testes, epididymis, and deferent ducts were separated and prepared
according to routine histological techniques for morphological characteriza
tion. The testis is covered by a capsule of fibromuscular connective tissue.
Spermatogonia are observed as spherical cells with round nuclei and loose
chromatin, and primary spermatocytes show dark cytoplasm, round nuclei,
and pale chromatin. Spermatids are seen as cylindrical or filamentous cells
with nuclei that may be highly condensed, ranging from round to oval. The
epididymis is observed as a coiled duct lined by a tall cuboidal epithelium
with stereocilia; the deferent duct shows ciliated pseudostratified cylindri
cal epithelium. The adrenal gland is found in the dorsomedial portion of the
testis. The histological structure of the reproductive tract of Paleosuchus
palpebrosus is similar to that of other reptiles’species.
References:

[1] Uetz P, Freed P, Hosek J. The Reptile Database [R]. 2020. Available at http://www.reptile-database.org. Accessed on June 2, 2021. [2] Campos Z, Sanaiotti T, Magnusson WE. Maximum size of dwarf caiman (Paleosuchus palpebrosus) (Cuvier, 1807), in the Amazon and habitats surrounding the Pantanal, Brazil [J]. Amphibia-Reptilia; 2010; 31(3): 439-442. https://doi.org/10.1163/156853810791769392. [3] Rugeles MA. Reproducción y crescimiento del cachirre Paleosuchus palpebrosus (Cuvier 1807) (Reptilia; Alligatoridae) en cautividad [J]. Memoria de la Fundación La Salle de Ciencias Naturale; 2003; 2001 (156): 119-129. Available at https://biblat.unam.mx/pt/revista/memoria-sociedad-de-ciencias-naturales-la-salle/ Accessed on June 5, 2021. [4] Guillette L, Milnes M. Recent observations on the reproductive physiology and toxicology of crocodilians. In: Crocodilian Biology and Evolution, p. 199-213. Grigg G, Seebacker F, Franklin C, Orgs. Chipping Norton, NSW, Australia, Surrey Beatty and Sons, 2000. [5] Nixon B, Anderson AL, Bromfield EG, Martin JH, Lord T, Cafe SL, Roman SD, Skerrett-Byrne DA, Eamens AL, De Lulis GN, Johnston SD. Gross and microanatomy of the male reproductive duct system of the saltwater crocodile Crocodylus porosus [J]. Reproduction, Fertility and Development; 2021; 33: 134-142. https://doi.org/10.1071/RD20303. [6] Gribbins KM, Elsey RM, Gist DH. Cytological evaluation of the germ cell development strategy within the testis of the American alligator, Alligator mississippiensis [J]. Acta Zoologica (Stockholm); 2006; 87: 59-69. https://doi.org/10.1111/j.1463-6395.2006.00220.x. [7] Cabrera AF, Garcia GCC, Gonzável-Vera M. Caractéristica histológicas del aparato genital de la baba (Caiman crocodilus crocodilus) [J]. Revista Cientifica; 2007; 17(2): 123-130. Available at http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0798-22592007000200004&lng=pt&nrm=iso. ISSN 0798-2259.Accessed on June 5, 2021. [8] Guerrero SM, Calderón ML, Perez GR, Pinilha MPR. Morphology of the male reproductive duct system of Caiman crocodilus (Crocodylia, Alligatoridae) [J]. Annals of Anatomy-Anatomischer Anzeiger; 2004; 186 (3): 235-245. https://doi.org/10.1016/ S0940-9602(04)80009-8. [9] Gribbins K. Reptilian spermatogenesis: a histological and ultrastructural perspective [J]. Spermatogenesis; 2011; 1(3): 250-269. https://doi.org/10.4161/spmg.1.3.18092. [10] Bian X, Zhanga l, Yang L., Yanga P, Ullaha S, Zhanga Q, Chen Q. Ultrastructure of epididymal epithelium and its interaction with the sperm in the soft-shelled turtle Pelodiscus sinensis [J]. Micron; 2013; 54-55: 65-74. https://doi.org/10.1016/j.micron.2013.08.009. [11] Di Lorenzo M, Barra T, Rosati L, Valiante S, Capaldo A, De Falco M, Laforgia V. Adrenal gland response to endocrine disrupting chemicals in fishes, amphibians and reptiles: A comparative overview [J]. General and Comparative Endocrinology; 2020; 297(1):1-11. https://doi.org/10.1016/j.ygcen.2020.113550. [12] De Falco M, Sciarrillo R, Virgilio F, Fedele V, Valiante S, Laforgia V, Varano L. Annual variations of adrenal gland hormones in the lizard Podarcis sicula [J]. Journal of Comparative Physiology; 2004; 190(8): 675-681. https://doi.org/10.1007/s00359-004-0528-1. [13] CFMV (Conselho Federal de Medicina Veterinária). Guia Brasileiro de Boas Práticas em Eutanásia em Animais - Conceitos e Procedimentos Recomendados [M]. Brasília: CFMV, 2012. 62p. Available at http://www. cfmv.gov.br/. Accessed on June 9, 2021. [14] Johnston S, Lever J, McLeod R, Oishi M, Collins S. Development of breeding techniques in the crocodile industry [M]. Camberra (AU): Union Offset Printing, 2014, 82p. [15] Lance VA. Reproductive cycle of the American alligator [J]. American Zoology; 1989; 29: 999-1018. Available at https://academic.oup.com/icb. Accessed on June 8, 2021. [16] Jones RC. Evolution of the vertebrate epididymis [M]. In: The Epididymis - From Molecules to Clinical Practice, p.11-33. Eds. Robaire B and Hinton BT. Kluwer Academic/ Plenum Publishers, New York, USA, 2002. [17] Guerrero S, Calderón M, Pérez G, Ramírez M. Annual reproductive activity of Caiman crocodiles fuscus in captivity [J]. Journal Zoology Biology; 2003; 22: 121-133. https://doi.org/10.1002/zoo.10080. [18] Sever DM, Freeborn LR. Observations on the anterior testicular ducts in snakes with emphasis on sea snakes and ultrastructure in the yellow-bellied sea snake, Pelamis platurus [J]. Journal of Morphology; 2012; 273: 324-336. https://doi.org/10.1002/jmor.11025. [19] Saccucci GA, Finol HJ, Garcia GC. Características histológicas del epidídimo de Baba (Caiman crocodilus crocodilus) sexualmente maduro [J]. Revista de la Facultad de Ciencias Veterinarias; 2011; 2(1): 5-12.Available at http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0258-65762011000100002&lng=es&nrm=iso. ISSN 0258-6576. Accessed on June 2, 2021. [20] González-Torrealba J, García C, Gisela C, Alvarado-Rico S, Díaz ME, Rodríguez A. Caracterización Morfológica de los Órganos del Sistema Endocrino de la Baba (Caiman crocodilus crocodilus): Aspectos Histológicos [J]. Revista de la Facultad de Ciencias Veterinarias; 2017; 58 (1): 3-9. Available at http://ve.scielo.org/scielo.php?script=sci_arttext&pid=S0258-65762017000100001 &lng=es&nrm=iso. ISSN 0258-6576. Accessed on June 8, 2021.

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