W. J. E. M. Costa
Rivulus giarettai, a new killifish from the Araguari River drainage, upper Paraná River basin, Brazil (Cyprinodontiformes: Rivulidae)Abstract
Rivulus giarettai, new species, from the Araguari river drainage, upper rio Parana basin, Brazil, is described. This is the first record of a rivulid in tributaries of the left bank of the Paranaiba river. Rivulus giarettai differs from all other species of the subgenus Melanorivulus by possessing a unique color pattern on flank in males, in which red pigmentation is arranged to form a vermiculate pattern. It is similar to species endemic to the central Brazilian plateau in having ventral process of angulo-articular vestigial, first epibranchial curved, and flank intense greenish blue or greenish golden, to purplish blue above anal-fin base in males; it differs from central Brazilian plateau species by a combination of reduction of black pigmentation on head and humeral region in males, 34-36 scales on the longitudinal series, 30-32 caudal-fin rays, 3-4 vomerine teeth, and caudal fin with bars in both sexes.
Costa, Wilson J. E. M.
Ichthyol. Explor. Freshwaters, Vol. 19, No. 1, pp. 91-95, 2 figs., 1 tab., 2008