The pointy-nosed blue chimaera has a huge geographic range 20 December 2016, by Kim Fulton-Bennett

and bone-like bits of cartilage. Like the chimaera from Greek mythology, which had a goat's head, a serpent's tail, and a lion's head, chimaeras are pretty weird looking. Even the common names for this group—ghost sharks, rabbitfishes, and ratfishes—sound like creatures one might see at Halloween. However, chimaeras are relatively common and widespread in the deep sea, with 38 known species around the world.

In 2009, MBARI researchers worked with scientists at the California Academy of Sciences and Moss Landing Marine Laboratories (MLML) to identify a This image of a pointy-nosed blue chimaera (Hydrolagus new species of ghost shark in the Gulf of California. cf. trolli) was captured by MBARI’s remotely operated Some of these same researchers had also seen vehicle Tiburon near the summit of Davidson Seamount, ghost sharks during remotely operated vehicle off the coast of Central California at a depth of about (ROV) dives off Central California. They weren't 1,640 meters. Credit: 2007 MBARI sure about the exact species, but they knew the fish did not look like either of the two species of ghost sharks previously identified from off the California coast. The deep sea is the largest contiguous habitat on the earth, covering two thirds of the earth's surface In a recent paper in Marine Biodiversity Records, and averaging over 3.5 kilometers deep. Because Lundsten and his colleagues presented evidence most deep-ocean waters are connected, many that the unidentified ghost shark they were seeing species of deep-sea animals have huge around Monterey Bay was, in fact the same species geographic ranges. For example, one deep-sea that had previously been identified only in the fish that was previously identified in the Southwestern Pacific. The paper cited three Southeastern Pacific has recently been found different chimaera experts who viewed the video around the Hawaiian Islands and off the coast of from MBARI ROV dives and said that they believed Central California, according to a new paper by the fish was a "pointy-nosed blue chimaera." MBARI researcher Lonny Lundsten and his colleagues. In their paper, researchers refer to the fish as Hydrolagus cf. trolli. The letters cf. indicate that the Scientists call this unusual fish Hydrolagus trolli, researchers believe the physical characteristics of but its common name is the pointy-nosed blue the fish they saw closely match the official species chimaera. First named in 2002, it is known to live in description for Hydrolagus trolli. Their alternative deep waters around Australia, New Zealand, and hypothesis is that the fish in MBARI's videos are an New Caledonia. But until the recent paper, it had entirely new species of ghost shark. not been officially identified anywhere in the Northern Hemisphere. The researchers note that they can't positively identify the ghost sharks in the ROV video without Chimaeras are unusual fishes. Like sharks, their actually collecting one of them and bringing it back bodies are not stiffened by bones, but by plates to the surface. This is much easier said than done,

1 / 3

because these fish are generally too large, fast, and agile to be caught by MBARI's ROVs. If and when the researchers can get their hands on one of these fish, they will be able to make detailed measurements of its fins and other body parts and perform DNA analysis on its tissue. This would allow them to either remove the cf. from their species description, or assign the fish to a new species altogether.

Close-up view of a pointy-nosed blue chimaera. The small dots around its head are believed to be sensory organs. Credit: MBARI

Similar looking, but as yet unidentified, ghost sharks have also been seen off the coasts of South America and Southern Africa, as well as in the Indian Ocean. If these animals turn out to be the same species as the ghost sharks recently identified off California, it will be further evidence that, like many deep-sea animals, the pointy-nosed blue chimaera can really get around.

More information: Amber N. Reichert et al. First North Pacific records of the pointy nosed blue chimaera, Hydrolagus cf. trolli (Chondrichthyes: Chimaeriformes: Chimaeridae), Marine Biodiversity Records (2016). DOI: 10.1186/s41200-016-0095-5

Provided by Monterey Bay Aquarium Research Institute APA citation: The pointy-nosed blue chimaera has a huge geographic range (2016, December 20)

2 / 3

retrieved 3 October 2021 from https://phys.org/news/2016-12-pointy-nosed-blue-chimaera-huge- geographic.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

3 / 3

Powered by TCPDF (www.tcpdf.org)