"Biologists call a small male fish who darts in to fertilize eggs a “sneaker,”, a medium male who resembles a female a “female mimic,”, and a large aggressive territorial male a “parental,” to place a positive spin of his egg guarding. Both the sneaker and the female mimic are “sexual parasites” of the parental male’s “investment” in nest construction and territorial defense. The sneaker and the female mimic are said to express a gene for “cuckoldry,” as though the parental male were married to a female in his territory and victimized by her unfaithfulness. In fact, a territorial male and the female who is temporarily in his territory are not pair-bonded. Scientists sneak gender stereotypes into the primary literature and corrupt its objectivity. Are these descriptions only harmless words? No. The words affect the view of nature that emerges from biology." —
Joan Roughgarden (2004) Evolution’s Rainbow: Diversity, Gender, and Sexuality in Nature and People, University of California Press, Berkeley
I feel like this is slightly relevant although more to do with heteronormativity than sexism. The study of animal behaviour still has a lot of both of these and it’s actively harmful to discussing both animal and human behaviour.