Husband or parasite?

We will talk about the fish “Photocorynus spiniceps”, which is one of the most unique and smallest animals in its ecosystem. Sexually mature males of this species of fish have a length of 6.2 to 7.3 mm, and in rare cases up to 9.3 mm. Females are much larger than their spouses and reach a length of up to 46mm.

A feature of males is their giant eyes and chemical organs of smell in the nose, which allow them to perceive substances.

After the transformation from larvae, males begin to search for females and, as soon as they find them, attach themselves to them with their sharp teeth. As a result, the tissues and blood vessels of partners grow together, and the male receives nutrition from the blood of the female. This phenomenon is known as sexual parasitism. The male also produces sperm with the help of gonads, which occupy almost the entire body, in order to fertilize the eggs laid by the female in the water.

The other side of the male Photocorynus spiniceps, also known as the Panama Photocoryne, is the unique relationship between males and females. In the natural habitat of this fish, males take part in caring for the young, providing them with food and protection. Also, males may participate in custody of the eggs until the young hatch. This distinguishes “Photocorynus spiniceps” from other species of fish, where usually only females take care of the young. This unique relationship between males and females is an example of parental behavior in fish.