- Source: Rubicundus lopheliae
Rubicundus lopheliae, the lophelia hagfish, is a species of jawless fish in the family Myxinidae.
Description
It was originally classified in the genus Eptatretus, but a 2013 analysis reclassified into the new genus Rubicundus, considered the most basal genus of hagfish. This is the only member of Rubicundus known from more than one specimen. This species can be identified by its lack of nasal-sinus papillae, five pairs of gill pouches, and elongated tubular nostril. Both the body and face of the fish are pinkish-orange in color. The most defining characteristic of this species is the elongated tubular nostril, something that has only been described in two other species, E. eos and E. lakeside. Both of these species also share the pinkish color of the Lophelia hagfish, as well as the five pairs of gill pouches. These similarities were the reason that this fish was originally classified in the Eptatretus genus. They were reclassified as a result of a 2013 study that examined the 16s rRNA gene in the Myxinidae. The study created a new genus called Rubicundus, that includes both Rubicundus Lopheliae and another pink hagfish species, formerly known as Eptatretus Rubicundus.
Distribution
This species is known to reside in the western North Atlantic, off the coast of the southeastern United States. More specifically, three specimens were captured off North Carolina and more were found in video observations off South Carolina. It inhabits cold-water coral reefs dominated primarily by Lophelia, as referenced in its specific epithet. The coral species from which this hagfish derives its name is found abundantly in their presumed habitat. The stars in the figure on the right mark where the specimens were found.
Biology
The discovery and classification of this species has helped further the understanding of hagfish biology as a whole. Previously, hagfish were thought to be bottom dwellers, burrowing into the substrate for protection. However, the finding of these hagfish in reefs offers new evidence that hagfish are able to find protection in other environments.
The elongated nostrils of this species are one example of this furthered understanding. The two other species of hagfish found with this elongated nostril also find protection in their environment without burrowing into the ground. Due to the large geographic distance between these species, it is likely that they evolved this trait convergently, each adapting to their own specific environments. The nostrils are used by hagfish in other environments to locate food in the ground, due to their reduced eyesight. The elongated nostrils provide the Lophelia hagfish with a similarly advanced sense of smell, aiding in their ability to find food in the reefs where they reside. The figure on the right shows these elongated nostrils.
Though not much is known about reproduction in this specific species, there is some description of reproduction in hagfish as a genus. At first, these fish were considered hermaphrodites, then dioecious, and it was not until more recently that they were found to develop specific gonads as juveniles. Though a small portion of the population are hermaphrodites, which could have led to the previous errors, this subset is also sterile.
Unfortunately, sampling of this species as well as the two others to which it is most closely related has only lead to a handful of specimens being collected at most. As a result, the rest of the aspects of their biology can only be assumed based on what scientists know about other species in their family.
Conservation Status
Because of the lack of research on this species, there has been no direct human intervention to manage for them. The most substantial known threat to this species is a threat to the whole habitat. Sand and gravel mining off the coast of the Carolinas can have detrimental effects on the coral populations that these fish use as a habitat. The mining can smother and kill the coral, destroying it and making it unlikely that more will grow in the future. Up until now, most of the mining has occurred relatively close to the shore, but there is concern that over the next decade the mining operations will move farther out into the ocean as a result of the greater deposits farther out. Another concern for this species is destruction of habitat from bottom trawling. Trawling for shrimp is very common off the coast of the Carolinas, and this practice can quickly and permanently destroy the coral reefs these fish need to survive. Oil and gas pipeline productions can also greatly impact this species. Their existence likely disrupts the species’ basic needs and could cause future environmental concerns due to spills or other malfunctions.
