New Addition To The Combtooth Blenny Genus

Ecsenius markalleni is the most recently described combtooth blenny from the genus Ecsenius, with its official taxonomic description published in the Journal of the Ocean Science Foundation 2026. Discovered inhabiting the isolated and biodiverse reef systems surrounding the Raja Ampat Islands in West Papua, Indonesia, this micro-endemic species represents a new addition to the most species-rich genus within the family Blenniidae. Anatomically, Ecsenius markalleni is best distinguished from its closest relative E. lineatus by a prominent, uninterrupted dark lateral band that runs continuously down the entire length of its body. E. lineatus, a common aquarium species, possesses a similar, but segmented stripe. Genetically, mitochondrial DNA sequencing of the cytochrome oxidase I (COI) gene reveals that this species possesses a distinct 4.1% genetic divergence from E. lineatus, which is native to the southwestern Indian Ocean.

[image: Left top – 𝐸𝑐𝑠𝑒𝑛𝑖𝑢𝑠 𝑚𝑎𝑟𝑘𝑎𝑙𝑙𝑒𝑛𝑖, n. sp., about 50 mm SL, Raja Ampat Islands, West Papua, Indonesia (G.R. Allen). Left bottom – 𝐸𝑐𝑠𝑒𝑛𝑖𝑢𝑠 𝑚𝑎𝑟𝑘𝑎𝑙𝑙𝑒𝑛𝑖, n. sp., about 50 mm SL: A) Havelock Island, Andaman Islands (G.R. Allen); B) Okinawa, Japan (M.V. Erdmann). Right – 𝐸𝑐𝑠𝑒𝑛𝑖𝑢𝑠 𝑚𝑎𝑟𝑘𝑎𝑙𝑙𝑒𝑛𝑖, n. sp., Triton Bay, West Papua, Indonesia; A) about 45 mm SL, banded pattern; B) about 45mm SL, partially coalesced segments; C) juvenile, about 20 mm SL (G.R. Allen).]