The oblique-swimming triplefin (''Forsterygion maryannae'') is a

triplefin Threefin or triplefin blennies are blenny, blenniiforms, small Percomorpha, percomorph marine fish of the family Tripterygiidae. Found in tropical and temperate waters of the Atlantic Ocean, Atlantic, Pacific Ocean, Pacific and Indian Oceans, the ...

, found along the north east coast of the

North Island The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

from depths of about 5 m to 50 m. They are the only triplefins not to spend most of their time resting on the bottom, instead swimming in loose schools of up to hundreds of individuals above rocky

reef A reef is a ridge or shoal of rock, coral, or similar relatively stable material lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic (non-living) processes such as deposition (geol ...

s. When swimming their head is higher than the tail, giving rise to their common name. Its length is between 5 and 8 cm. The body is orange-brown with a red tinged head, a black eye, and a wide black lengthwise stripe on each flank. Oblique-swimming triplefins are plankton feeders taking their tiny

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

and

euphausid Krill ''(Euphausiids)'' (: krill) are small and exclusively marine crustaceans of the order Euphausiacea, found in all of the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often a ...

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

food in mid-water. Its

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours the underwater photographer Maryann W. Williams.

References

* * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) Oblique-swimming triplefin Endemic marine fish of New Zealand Fish described in 1987 {{Blenniiformes-stub