Dusky Finless Ray

10/6/2018

Elasmolab (Universidad Austral de Chile).

I am so excited to introduce you to this species-- because our good friend, and Behind the Fins interviewee, Sebastian Kraft is going to be talking about this animal (and a few others in the future)! See his interview here.

This is a relatively small species of deepwater skate: the maximum registered size it attains is 57 cm. Males mature at a length of 51-52 cm, while females do this closer to the maximum registered length, at 55-57 cm approximately. The disc (the body portion between the tip of the rostrum and the cloaca) is wide, approximately 1.5 times the disc length. In addition to this, it’s most conspicuous feature, as stated in the original description by de Buen in 1959, might be the notoriously long and thin tail: it can be up to two times the disc length. Additionally, as the verancular name suggests, it lacks dorsal fins. The color of the body is dark grey or brown dorsally and lighter in the ventral portion.

Modified image from the distribution that is available in the IUCN Red List.

This skate is found in the southeastern Pacific, ranging from the Galapagos Islands to Valparaíso, Chile, where the holotype of the species comes from (yay South America!). Here, we’d have to descend to somewhere between 300 and 960 meters to start seeing it. Consequently, it comes as no surprise that reports are scarce and virtually nothing is known about the reproductive biology: both the genus name Gurgesiella and the species name furvescens were described only 59 years ago. Therefore, its geographical range is patchy from these very few, isolated catches, but it’s likely it’s more broadly distributed.

Despite the evident absence of information about this species, because it’s more isolated from the fishing activity relative to shallower species, it’s currently catalogued as ‘Least Concern’ (LC) by the IUCN.

FUN FACT: According to FishBase, the genus name of this skate comes from the latin word gurges, which means abyss or whirpool. 