Gibbonsia montereyensis
The Crevice Kelpfish
is a species of ray-finned fish, a blenny found from the family. It is found in coastal waters from British Columbia to Baja California. This species inhabits rocky, algae-covered areas on exposed coasts, particularly where seagrass and algal growth are abundant. G. Montereyensis often exhibits coloration that matches its environment.
Taxonomy
The Crevice Kelpfish is a member of the family Clinidae and the genus gibbonsia. There are three recognized members within this genus: G. Montereyensis, G. Elegans, and G. Metzi.
Description
Gibbonsia monteryensis is small marine fish with a maximum length of about 11 cm. This makes them the smallest member of its genus. It has an elongated, laterally compressed body with relatively small pelvic and caudal fins. Their bodies are covered with small cycloid scales. Crevice kelpfish have a continuous dorsal fin, extending from the head to the caudal peduncle. Along their dorsal fins they have 34-36 spines and 5-8 rays. The dorsal spines on their head are relatively long compared to their other spines which give them the appearance having a sort of crest on their heads. Like other kelpfish, G. montereyenesis have fleshy, hairlike tufts above their eyes called cirri. Its anal fin is elongated consisting of 34-36 spines and 5-8 rays. They have pelvic fin spines that are separate from their main pelvic fin and sit slightly in front of the main fin.
Their mouths are small and terminal. Crevice kelpfish have small, fixed, conical teeth. One of the few distinguishing features of G. montereyensis that differentiates it from other members of gibbonsia is that they lack scales on their caudal fin.
Color variability is high in crevice kelpfish and can include brown, reddish, green dark, and silver. The typical pattern of G. montereyensis is dark vertical bars running down the length of the body, scattered dark spots, and a dark ocellus above the lateral line and behind the pectoral fin. Gibbonsia as a genus are sexually dichromatic, differing in belly color between males and females.
Crevice kelpfish are capable of changing colors but there are no definitive studies on the timing and mechanism that allows them to change colors. Similar species such as G. elegans have been seen to be capable of changing their colors over the course of several weeks, likely independent of diet. Their color often varies by season as they are often red in winter when red algae dominates and green in the spring when green algae dominates. G. montereyensis are also susceptible to chromotaforma which is a tumor of pigment cells that develops in their cutaneous layer.
Distribution
Gibbonsia montereyensis range extends along the coastal, Eastern Pacific from British Colombia to Central Baja California. South of Point Conception crevice kelpfish are only found on offshore islands and parts of Baja California where upwelling keeps the water colder. They are only occasionally found in tidepools as they prefer deeper waters compared to other members of the genus gibbonsia. It typically inhabits the intertidal zone to subtidal zone at depths up to 20 meters.
Ecology
Crevice kelpfish spend much of their time anchored onto algae covered rocks using their pectoral spines where they can successfully camouflage using their coloration to camouflage with the algae. They do not have high mobility, and they are a common prey for larger marine predators making their camouflage an important defense. G. montereyensis are benthic, invertebrate feeders and their diet consists of isopods, amphipods, crabs, copepods, shrimps, limpets, mollusks, fish eggs and polychaetes.
Conservation Status
G. montereyensis is a species of Least Concern by the IUCN. However, a study found that Crevice kelpfish will likely be affected by warming ocean temperatures as they prefer colder water. They have some tolerance to warmer waters but not as much as other species within gibbonsia. A study found that they were less adaptable to cold and warmer water than their counterpart Gibbonsia metzi. Heat stress can cause them to die very quickly if the water temperature reaches a level outside of their tolerable range. A new type of parasitic copepod may affect them as it has been found on two other species of gibbonsia, but it is has not been found on G. monteyensis'' yet.