Parablennius gattorugine, the Tompot Blenny, is a marine fish species of combtooth blenny from the north eastern Atlantic Ocean, coastal waters off western Europe, North Africa, the Mediterranean Sea and thus the Maltese Islands.
The specific name was first used by Francis Willughby in 1688 after he had observed these blennies in Venice and heard them being called gatto ruggine. Although he was afraid that he did not fully understand the name, he translated this as „rusty cat“ or „rust colour“. However the actual name is gatto rusola or gotto rosula which is a local name for blennies in general along the Adriatic coast of Italy and which is a diminutive of gotto roso meaning „thick throat“.
The Tompot Blenny is a relatively large blenny with an elongated body, large head and large eyes. It grows to up to 30 centimetres in length. The eyes are bicoloured with their top part being brown and the bottom part white. There is a single branched tentacle over each of its eyes. Apart from the tentacles over the eyes, there are also tentacles over the nostrils.
Parablennius gattorugine is mainly yellow-brown in colour, although occasionally it is greenish and is marked with at least seven dark bars starting at the dorsal fin and reaching the belly. The lateral line is continuous but becomes broken towards the tail. Every single individual has a unique set of markings on the scales of the face, which means that studies of their biology can identify individuals.
The breeding males become chocolate brown in colour and develop bulb-like glands on the spines of the anal fin. The Tompot Blenny has relatively large pectoral fins. The dorsal fin runs the length of its body and is divided into two halves by a shallow notch. The anterior portion of the fin contains the spiny rays, while the posterior portion contains the soft rays. The dorsal fin has 13 to 14 spines and 17 to 20 rays, while the anal fin has 2 spines and 19 to 23 rays.
Tompot Blennies are very territorial. Their territories are centred around a crevice in the rocky reef which the fish uses for shelter. They occur in shallow seas at depths of 3 to 32 metres, although smaller specimens occur in rockpools. The latter may be found above the low tide mark at very low tides, sheltering under boulders or among exposed vegetation.
Parablennius gattorugine has sharp, comb-like teeth which it uses to scrape food from the substrate. It feeds on sea anemones and on other invertebrates such as prawns and other crustaceans. Tompot Blennies are crepuscular, being active mainly at dawn and at dusk. As most fish, they harbour several species of parasites, including the capillariid Nematode Pseudocapillaria bainae.
Tompot Blennies spawn from March to May. The males mate with several females and guard their eggs. The eggs are demersal and like those of all blennies they stick to the substrate by a filamentous adhesive patch. The male guards the eggs until the larvae hatch, usually about a month after laying. The males defend their territories from other males and often fight each other, frequently receiving injuries. When breeding, the males develop pale cauliflower like glands on their anal fins which are believed to play a role in attracting females and in cleaning the eggs.
Photo taken by Brian Azzopardi