Haematozoa of Fishes in Humboldt Bay, California

Five hundred seven fish representing 45 species from Humboldt Bay, California (USA) were examined for blood parasites. Four fish (< 1 %) from two species were infected. Haemogregarina leptocotti sp. n. is described from one of 33 staghorn sculpin (Leptocottus armatus). Haemogregarina roelofsi sp. n. is described from three of 15 black rockfish (Sebastes melanops). Gametocytes of H. leptocotti sp. n. averaged 6.1 × 2.1 μm with a 2.7 × 1.7 μm oval nucleus; those of H. roelofsi sp. n. averaged 5.5 × 2.7 μm with a 2.5 × 2.2 μm rectangular nucleus. Neither species of parasite had distinct chromatin granules, a polar cap, or more than one gametocyte in an infected cell. Haematozoa are relatively rare in fishes of the northeastern Pacific Ocean.