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Pectoral fin size in a fish species with paternal care: a condition‐dependent sexual trait revealing infection status
Author(s) -
Bakker Theo C. M.,
Mundwiler Beat
Publication year - 1999
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1046/j.1365-2427.1999.00403.x
Subject(s) - fish fin , biology , gasterosteus , paternal care , beak , zoology , population , acanthocephala , fish <actinopterygii> , helminths , fishery , demography , genetics , pregnancy , sociology , offspring
Summary 1. The three‐spined stickleback, Gasterosteus aculeatus L., is a territorial fish with exclusive male parental care. Males oxygenate the eggs with fanning movements of their pectoral fins. The present authors investigated whether the apparent sexual differences in the functional demands of the pectoral fins have resulted in sexual differences in fin size. If males have relatively larger pectoral fins, females may use this as a signal to aid their mate choice for good fathers. Therefore, further objectives were to study the condition‐dependency of relative pectoral fin size in males and the relationship with male parasite load. 2. Reproductively active males possessed relatively larger pectoral fins than females in both wild‐caught and laboratory‐bred fish. 3. In the field, caring males with relatively large pectoral fins were in better physical condition and had more food in their stomachs. 4. Relatively small pectoral fins and poor body condition were associated with infection by the intestinal parasite Pomphorhynchus laevis (Acanthocephala), the prevalent parasite species in the study population.