Rabbitfish- Strange Sharks in the Year of the Water Rabbit

新年好    Happy New Year. May the year of the water rabbit be auspicious for people and wildlife.

2023 is a year of the Water Rabbit, beginning on Chinese Lunar New Year January 22 and ending on Feb 5. The sign of Rabbit is a symbol of longevity, peace, and prosperity in Chinese culture. 2023 is predicted to be a year of hope.

Happy New Year. May the year of the water rabbit be auspicious. Please celebrate without shark fin soup for your health and the health of the ocean. Art by Justyn Triest

We hope the year of the water rabbit brings hope for sharks without shark fin soup, and prosperity for lesser known species of Cartilaginous fish in the year of the Water Rabbit like the Rabbitfish!

The Rabbitfish is a Chimaera, an ancient cousin to sharks. Chimaera, also known as ghost sharks, rat fish, elephant fish and rabbit fish, are a specialized group of cartilaginous fish. Grouped together in the Class Chondricthyes, the two sub groupings include the sharks and rays in the subclass Elasmobranchii, and the subclass the Holocephali in which the Chimaera are included.

Once more widely represented a in the ocean, these are the only surviving group in the subclass of the order Chimaeriformes. The Chimaeras, include the rat and rabbit fishes in the genus Chimaera, and the elephant fishes in the genus Callorhinchus. Generally a deep water species they are also found in temperate to cold waters of all oceans. They also live in estuaries, coastal waters, continental shelfs and depths of over 8,000 feet.

Spotted Ratfish (image Wikicommons)

In California, our own kind of rabbitfish is known as the spotted ratfish (Hydrolagus colliei) found along the Pacific coast of North America. Named after their long rat-like tail, the ratfish is a bottom dweller and lays leathery egg cases in muddy or sandy areas. While mainly a deep-water species, it occurs at shallower depths in the northern part of its range and are sometimes seen by SCUBA divers at night. 

The name derives from Greek mythology, referring to a being with a body derived from several animal shapes.

She was of divine stock, not of men, in the fore part a lion, in the hinder a serpent, and in the midst a goat, breathing forth in terrible wise the might of blazing fire.”

Homer, The Iliad
Artist rendition mythological Chimera. OpenClipart-Victors from Pixabay

In general, Chimaera are weak swimming deep sea fish with slender tails and use sweeping movements of their large pectoral fins. They feed on benthic invertebrates, small fish and dead material. Lacking a stomach, their food passes directly into the intestine. This fish grows to a length of almost a meter (three feet), and has a beautiful silvery-bronze coloration sprinkled with white spots. With large emerald eyes in a broad face with large teeth they look like a rabbit coming and a rat going: truly chimerical!

Unlike more modern species of sharks, the Chimaera have only 4 gills with one external opening. Their upper jaws are fused to their skull and they have 3 pairs of large permanent grinding tooth plates. Their skin is smooth lacking dermal denticles. Males have pelvic claspers similar to sharks, but also have an accessory clasping organ called cephalic claspers (tenacula) on the head. These are used to hold the female during copulation.

Most Chimera species are caught in nets and trawls as bycatch, but are also targeted for their liver oil from which squalene is derived. The Elephant fish (Callorhinchus milii), is a commercially caught Chimaera off New Zealand, South Australia and Southeastern Australia. They are eaten as filets or fish and chips. Growing to a length of about 4 feet, the Elephant fish lives in cold waters over the continental shelves as deep as 660 feet, but moves inshore to lay eggs.

Dr. David Ebert of the the Pacific Shark Research Center (PSRC) at Moss Landing Marine Laboratories (MLML) has described numerous previously unknown species of rabbitfish and other “Lost Sharks“, many from deep sea trawls or discovered in fish markets.

We hope the year of the water rabbit brings longevity for sharks without shark fin soup, and prosperity for lesser known species like the Rabbitfish!