Acentrophryne longidens

Acentrophryne longidens 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. dolichonema by the possession of a shortener appendage on the tip of the esca, this having a length equivalent to 2.3-2.5% of the standard length as opposed to 27.6% to 35.7% in A. dolichonema, and a shorter illicium, which has a length equivalent to between 35.7% and 54,9% of the standard length conmpared to 63.6% to 70.5% in A. dolichonema. They also have a broader head and more fin rays in the pectoral fin, 18 or 19 compared to 16 for A. dolichonema. This species has a maximum published standard length of 5 cm (2.0 in).

Acentrophryne longidens is known from two specimens which were collected from two separate localities in the Eastern Pacific Ocean, in the Gulf of Panama and south of Cabo Blanco in Costa Rica. Both specimens were collected at depths between 1,250 and 1,280 m (4,100 and 4,200 ft).

== References ==

Acentrophryne longidens 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 'this species but its identity is now left open as Acentrophryne sp. as it was somewhat intermediate between this species and Acentrophryne dolichonema. 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.