Amatitlania siquia

Amatitlania siquia is a species of cichlid fish native to Central America. Males can be recognised by black melanin-based stripes, and females by an additional bright orange spot on the abdomen. The size and pigmentation of these markings relate to how proactive an individual is: darker stripes in males and smaller spots in females are characteristic of more proactive fish. Some males use alternative reproductive tactics, making their appearance similar to females, and these males have gonadosomatic indices 16 times larger than parental males and 3 times higher than females. In 2019 scientists showed that members of this monogamous species develop a pessimistic attitude when their partner is absent.