Rippled Rockskipper

Istiblennius edentulus, commonly known as the rippled rockskipper, is a unique species of combtooth blenny found in the coral reefs of the Pacific and 🌊 Indian Oceans. It is also referred to as the rippled blenny, smooth-lipped blenny, toothless blenny, or coral blenny. Males of this species can grow up to 16 cm (6.3 in) in total length, while females reach up to 13.2 cm (5.2 in) in standard length.

These fish inhabit marine and brackish waters, typically residing in shallow rocky reef tops at depths ranging from 1 to 5 meters (3.3 to 16.4 feet), with a preference for around 1 meter (3.3 feet) deep. Juvenile rockskippers can be found in tidal pools, where they exhibit a fascinating appearance. Their bodies display grey bars, and their heads have small blue and reddish streaks behind the eyes.

The species has distinct features such as 12 to 13 dorsal spines, 19 to 21 dorsal soft rays, 2 anal spines, and 21 to 23 anal soft rays. Males have a darker, dusky coloring with 5 to 6 pairs of bands across their bodies and pale stripes on the dorsal fin, sometimes developing a crest. Females are paler, with their bands breaking into spots towards the back, and their dorsal fins are often spotted.

Interestingly, the rippled rockskipper is capable of facultative air-breathing, meaning it can breathe air when necessary. This adaptation allows them to live in intertidal zones, where they are often found hiding in cracks or holes when they’re not feeding. They are known for their energetic skipping behavior, leaping from one pool to another when pursued. This fish can survive out of water for a while by hiding under rocks or seaweeds and continues to breathe air during these intervals. Their diet primarily consists of filamentous algae.

As an oviparous species, the rockskipper lays eggs that are demersal and adhesive, attaching to substrates with a filamentous pad. The larvae are planktonic and can often be found in shallow coastal waters.

Rockskippers are found throughout the Indo-Pacific region, from the 🌊 Red Sea and East Africa to the Line, Marquesan, and Tuamoto Islands (🇵🇫 French Polynesia), extending north to southern 🇯🇵 Japan and south to Lord Howe and Rapa. The genus name Istiblennius comes from Greek, where 'istios' means sail and 'blennios' means mucus, hinting at their slimy biology.