L. Forró szerk.: Miscellanea Zoologica Hungarica 7. 1992 (Budapest, 1992)

Borroto Páez, R., Camacho Pérez, A.; Ramos García, I.: Variation in three populations of Capromys pilorides (Rodentia: Capromyidae), and the description of a new subspecies from the south of the Isle of Youth (Cuba)

This form may be considered as very abundant in the south, due to the fact that it is well protected by controlled and restricted access to this area and also by the diversity and abundance of resources in this habitat. The distribution of the northern form C. p. relictus has become restricted in recent times. It used to be quite abundant in small hills and ridges (Sierra de las Casas, La Siberia, etc.), where it lived in cliffs with hummock-type vegetation. However, at present it is mainly found in low and marshy zones and in estuaries, where the red mangrove (Rhizophora mangle) is predominant. There it can be found alone, in couples or with their young, among the roots and branches of mangrove. It is not abundant probably due to human influences (mainly hunting) and to the relative scarcity of food resources in this habitat. Another important aspect is the existence of a tick which is only found among southern population of conga hutias in the Isle of Youth, described by v_erny (1966) as Ixodes (Alloidoixodes) capromydis. The subgenus is endemic. Distribution From the point of view of geographic distribution, the populations of conga hutia in the Isle of Youth may be considered as two large allopatric populations, separated by the sandy lowland range bordering the large Ciénaga de Lanier swamp. This is clearly a barrier between these populations, since it is unsuitable for the species. Contact or overlap, and thus genetic exchange is only possible at the extreme eastern and western points of this area. However, in the coastal habitat of these points the northern population is quite scarce, which limits possible contact with the southern form. The northern and southern regions of the Isle of Youth have different geological histories. The northern zone is the oldest and, according to Iturralde-Vinent (1988) is constituted by folds (emerged mountain chains) formed 45 million years ago, before the early Eocene period. The southern part of the Isle, in contrast, is rather recent and of sedimentary origin. Therefore C. p. relictus is probably the older form from which the southern population originated. A rather recent separation would explain the similarity of these populations regarding allozyme frequencies, referred to above, especially the data for the PGI locus which differentiates the Isle of Youth populations from all other populations of the conga hutia (Camacho & Borroto 1989). Qualitative cranial characters also indicate similar tendencies, suggesting close phylogcnetic relations. However, there are also some similarities between C. p. pilorides from Ciénaga de Zapata and the southern form. They may perhaps indicate some kind of genetic exchange. This may be explained by the fact that both regions, Ciénaga de Zapata and the southern part of the Isle of Youth, originated practically at the same time, and communication between them might have then existed (IturraldeVinent 1988). Description of a new subspecies of Capromys pilorides Taking into account differences in quantitative morphological characters, habitat and other features, and the fact that Allen's (1911) description of C. pilorides relictus does not conform with several important traits of the population of C.