Tripterygiidae
Tripterygiidae, commonly referred to as threefin or triplefin blennies, represent a family of diminutive percomorph marine teleosts. This family, disseminated across the tropical and temperate zones of the Atlantic, Pacific, and 🌊 Indian Oceans, encompasses approximately 150 species distributed among 30 genera. The nomenclature of the family Tripterygiidae is rooted in the Greek term "tripteros," which translates to "with three wings," an allusion to a distinctive anatomical feature.
Morphologically, threefin blennies exhibit an extended body typical of blennioids, distinguished from their conspecifics by a tripartite dorsal fin—the first two segments of which are spinous. They are characterized by diminutive, slender pelvic fins situated beneath the gills with a single spine, whereas the substantial anal fin may be armed with one or two spines. The pectoral fins are notably large in comparison to body size, and the caudal fin presents a rounded aspect. Notoclinus fenestratus, known commonly as the 🇳🇿 New Zealand topknot, is the preeminent species within this family, achieving lengths up to 20 centimeters, although the majority of species do not surpass 6 centimeters.
This family's vivid coloration, frequently a mechanism of environmental camouflage, has secured their popularity within the aquarium trade. Threefin blennies, classified as demersal fish, predominantly inhabit benthic zones, residing on substrata such as coral formations and rocky outcrops. These teleosts are primarily located in shallow, lucid waters that receive copious sunlight, including lagoon systems and seaward reef environments. Due to their skittish nature, these fish are inclined to seek refuge within rocky cavities when presented with potential threats.
The behavioral patterns of threefin blennies are characterized by diurnal activity and territoriality. It is noteworthy that sexual dichromatism is prevalent within many species, with females exhibiting more subdued coloration relative to their male counterparts. In certain species, males will also display an elongated second dorsal fin. The dietary regimen of threefin blennies largely consists of small invertebrates.
