Convict Blenny, Pholidichthys leucotaenia
The convict blenny lives in tunnels around coastal reefs and in shallow lagoons of the Western South Pacific, mainly from the Philippines to the Solomon Islands. The young of this fish will often swim in schools around the reef heads and ledges so tightly packed together they will look like one organism.
This species, sometimes called a blenny and sometimes called a goby, actually it is neither. It is in a classification alone with one other species called a worm blenny. The convict blenny is eel-like in shape having a black or dark blue body. The young will have a white stripe length-ways of the body, but as it grows the stripe will change to multiple white vertical bands and spots giving it the name convict blenny. The adult can grow to 24 inches in length and have a life span of more than three years.
During the day the young convict blenny will swim up to a 150-foot radius of the nest to feed on plankton while the adult will stay in the tunnel to feed and do house cleaning by gathering mouthfuls of debris and spit it away from the nest. At night the young will return the tunnel nest and hang from the roof with the mouth by a small strand of mucus. Frequently the adult will gather up the young in the mouth then spit them out again.
Spawning occurs within the nest once a year after the fish is over one year old. The egg is a white colored adhesive mass and is less than a 1/8 inch in diameter. Hatching of the larvae occurs 7 – 10 days after fertilization. The larvae are colorless except for the eye and are around 1/4 inch in length having a small yolk sac. Around 26 days later the larvae will morph into a young convict blenny.
Image Credit: Haplochromis/Wikipedia (CC BY-SA 3.0, 2.5, 2.0 1.0)