Expedição à restinga de Quissamã, litoral norte do Rio de Janeiro, dados citogenéticos de pequenos mamíferos implicações conservacionistas para uma espécie ameaçada de extinção

Abstract

The northern coast of Rio de Janeiro hosts one of Brazil's largest restinga ecosystems, part of which is protected by the Jurubatiba National Park, spanning the municipalities of Carapebus, Macaé, and Quissamã. This coastal Atlantic Forest ecosystem, characterized by heterogeneous vegetation and sandy soil, faces intense anthropogenic pressure leading to habitat degradation. Among the vertebrates inhabiting this restinga is Cerradomys goytaca, an endemic and endangered rodent species. The vertebrate fauna in this region remains poorly studied, although members of the orders Didelphimorphia, Chiroptera, and Rodentia play vital ecological roles in local plant communities. In April 2009, a field expedition to the restinga of Quissamã aimed to study small mammals, with cytogenetic analyses performed on five species: Didelphis aurita, Marmosa paraguayana, Glossophaga soricina, Cerradomys goytaca, and Rattus rattus a synanthropic species. Mitotic chromosomes were prepared from bone marrow cells, stained with Giemsa, and examined under an optical microscope. Karyotypes were digitally assembled and compared with existing descriptions. The results confirm the karyotypic pattern previously described for C. goytaca in Beira de Lagoa, outside the boundaries of Jurubatiba National Park. The karyotypes obtained were as follows: Marmosa paraguayana (2n=14, NF=20), Glossophaga soricina (2n=32, NF=60), Cerradomys goytaca (2n=54, NF=66), and Rattus rattus (2n=38, NF=58).

Given the ongoing habitat loss due to human activities, our findings support the need to consider establishing new protected areas to mitigate the extinction risk for this threatened endemic species.