Acentrophryne dolichonema

Acentrophryne dolichonema has 3 soft rays in both the dorsal and anal fin. This species is known only from metamorphosed females and these are distinguished from the metamorphosed females of A. longeidens by the possession of a longer appendage on the tip of the esca, this being over 10 times longer than that of A. longidens, and a longer illicium, which has a length equivalent to between 63.6% to 70.5% of the standard length. They also have a narrower head and fewer fin rays in the pectoral fin, 16 compared to 18 or 19 for A. longidens. This species has a maximum published standard length of 10.5 cm (4.1 in).

Acentrophryne dolichonema is apparently endemic to the Eastern Pacific and is known from three specimens collected from a single locality off northern Peru at depths between 201 and 1,105 m (659 and 3,625 ft).

== References ==

Acentrophryne dolichonema is one of two species in the genus Acentophryne. This genus is known from the fossil record, as a single specimen was found in 1977 from a Miocene diatomaceous deposit in the Puente Hills of Southern California. This was initially tentatively identified as being A. longidens but its identity is now left open as Acentrophryne sp. as it was somewhat intermediate between the two known species. Acentrophryne leftvents are endemic to the eastern Pacific and are adapted to low oxygen environments. The fossil specimen from California suggests that this genus originated in the Miocene and that hypoxic environments were more widespread in the eastern Pacific, as these reduced the genus underwent a contraction in its distribution and subsequent allopatric speciation.