Rockskipper fish or Combtooth blennies Blenniidae
Category
- Rocky Shores
Description
Rockskippers can commonly be found on rocky shores outside of the water hopping from rock to rock. Most rockskippers are part of the combtooth blenny family, Blenniidae. This family is the largest in its suborder. Blennies hold unique traits, which range from mimicry and hopping over terrestrial rocks to adopting separate colours for courtship. Combtooth blennies have elongated bodies with no scales, large eyes and a rounded head. They have large continuous dorsal fins with up to 17 spines. They have small, slender pelvic fins located before their enlarged pectoral fins, while their tails are rounded. As their name would suggest, combtooth blennies are noted for the comb-like teeth which are close-set on a single row on each jaw.
Habitat and ecology
Blennies tend to dominate intertidal and inshore zones, where they are experts in occupying holes and crevices. Most blennies have colours that blend in with their environment. Some can escape predators by hopping over rocks from pool to pool. Male blennies tend to be larger than female ones, and in some species, they also have a larger head. Courtship is usually initiated by females by assuming new colours for spawning. In turn, male blennies may entice female blennies into their territory in a cave, crevice or other shelter using various courtship behaviours so that the female may lay their eggs in their sheltered territory. After fertilization, the males are usually the ones to guard the eggs and these may include broods from several females. Once the eggs hatch, the larvae enter a planktonic stage before becoming young pelagic fishes, which look different from their adult form. Once they enter their coastal habitat, they will undergo their final transformation into their adult form. Combtooth blennies are predominantly bottom dwellers that feed on algae and small invertebrates. Rockskipper blennies usually graze algae off coastal rocks.
Conservation status and threats
There are currently no major threats to blennies. Their status on the IUCN Red List is not assessed. Coastal alteration works may affect the local population of rockskipper blennies if the rocky shore habitat is modified. Rising oceans induced by climate change may also affect the blennies.
Did you know?
Males may also use different spawning colours as a sign of courtship. Some will bob their head up and down or swim in an undulating motion at the entrance of their sheltered territory, crevice or cave to entice females in.
