Microlipophrys nigriceps is a small fish belonging to the family Blenniidae that lives on rocky bottoms and shallow rocky walls (rarely found at depths greater than 6 meters) of the Mediterranean Sea.
The body of Microlipophrys nigriceps is elongated and slender, reaching up to 4 cm in total length. Its head is more or less rounded and it has large eyes located laterally in an elevated position. On its head we will not be able to find neither ocular tentacles nor any kind of appendage, nor a black spot or ocellus behind its eyes. This species has a single dorsal fin formed by a spiny region of 12 rays and a region of 14-16 soft rays. The height of the spiny region and the soft ray region is more or less equivalent, with an obvious incision or notch between the two areas. The pectoral fins have 12 rays. As for the coloration of Microlipophrys nigriceps, it is completely red-orange with a black head with a grayish-blue lattice pattern. The fin rays are red-orange with transparent interradial membranes on all fins except for the caudal fin which has a red-orange hue.
Lacking a swim bladder, Microlipophrys nigriceps moves along the bottom in a leaping motion. When the specimen is at rest, it rests on the substrate by means of the pectoral fins. It is a rather territorial species, which will defend its small territory, usually formed by a crack or crevice in the rock and a small area around it.
During the breeding season, male specimens of Microlipophrys nigriceps have bright yellow spots located on both cheeks.
It can be confused with Trypterygion melanurus as it has the same body color. The most noticeable difference between both species is in the dorsal fin, being unique in the case of Microlipophrys nigriceps, and being divided into 3 dorsal fins in the case of Trypterygion melanurus.
Some authors have described two subspecies within Microlipophrys nigriceps, although this is not universally accepted. On the one hand the subspecies Microlipophrys nigriceps cypriacus, which would be located in the southern Mediterranean Sea and would be differentiated by the presence of a black spot on the tail; and on the other hand the subspecies Microlipophrys nigriceps nigriceps, located in the northern Mediterranean Sea and lacking this black spot on the tail.Photos: