Open AccessDifference in parasite load and nonspecific immune reaction between sexual and gynogenetic forms of Carassius auratus
Author(s) -
HAKOYAMA HIROSHI,
NISHIMURA TEIICHI,
MATSUBARA NAOTO,
IGUCHI KEI'ICHIROH
Publication year - 2001
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/j.1095-8312.2001.tb01326.x
Subject(s) - biology , parasite hosting , immune system , immune reaction , zoology , sexual dimorphism , immunology , world wide web , computer science
For coexistence, the sexual form in sexual/asexual complexes needs short‐term advantages that can compensate for the two‐fold disadvantage of sex. Higher mortality in the asexual form due to a higher parasite load will provide an advantage to the sexual form. In Lake Suwa, Japan, the parasite load (Metagonnimus sp.; Trematoda) of triploid gynogenetic females of Carassius auratus was significantly higher than that of diploid sexual females. In an immunoassay using healthy wild fish that were conditioned for 1 month in laboratory tanks, the nitroblue tetrazolium (NBT) immune reaction of sexual females was significantly higher than that of gynogenetic females. The NBT activity indicates the abundance of oxygen radicals from phagocytes, and hence the level of immune activity of the phagocytes. We suggest that the higher parasite load of the gynogenetic form is in part due to the lower immune activity of the phagocytes (nonspecific immune reaction) in the gynogenetic form compared to the sexual form.