MORPHOLOGY AND PHYLOGENY OF SWAMP BUFFALOES (Bubalus bubalis) IN CALAYAN ISLAND, CAGAYAN

Abstract

Swamp buffalo is considered as a single and homogenous breed in the Philippines. The study aimed to establish the morphological and molecular characteristics of swamp buffaloes in Calayan Island, Cagayan. Morphology and morphomet­rics of body, horn, face and neck were recorded. A total of 64 sequences from the mtDNA cytochrome c oxidase I (COI) and 21 SRY sequences were includ­ed for phylogenetic analysis for maternal and paternal lineages, respectively. On average, males have significantly greater values (P<0.05) than females for traits measured except for height and distance and width of horns which in­dicated sexual dimorphism. The coat color for gray is predominant over the black and brown. The inferred phylogenetic tree based on COI sequences, with high statistical support (BP=100%), showed one clade and separated by two clusters of swamp and riverine buffaloes. This showed the usefulness of COI and SRY genetic markers to discriminate breeds of B. bubalis swamp-type with riverine-type and revealed the high affinity of swamp buffaloes in the Calayan Island with those in the PCC Institutional Herds and Asian countries. There­fore, the combined data on the morphological and molecular characteristics showed that the buffaloes in Calayan Island are of swamp-type buffaloes and suitable for the establishment of the Philippine carabao conservation.