Santana knew that an oarfish was a cool and unusual find, so she dove to the bottom, grabbed it by the tail, and dragged the dead fish onto the beach. After recruiting some help, she and other CIMI crew managed to wrestle the 18-foot long oarfish onto the beach at Toyon Bay.
About a week later, a second dead oarfish washed ashore near Oceanside, about 40 miles north of San Diego.
 |
| (*Click* to embiggen) CIMI crew with the oarfish that washed ashore at Toyon Bay, Catalina Island |
What are oarfish?
Oarfish are ray-finned fishes, a diverse group that include most of the fish you know and eat. The group includes salmon, tuna, guppies, bass, and minnows. Oarfishes are in the Order Lampriformes, a small group that include the opah and ribbonfishes. The oarfish are in their own family (Regalicidae, meaning "royal") within this order.
There are three species of oarfish:
- Giant oarfish (Regalecus glesne) - found throughout the world, mainly in subtropical waters
- Slender oarfish (Regalecus russelii) - found in the Pacific Ocean, including California waters
- Streamer fish (Agrostichthys parker) - found in temperate waters of southern oceans
Oarfish Ecology
Oarfishes look like monsters, but pose no threat to people. All species lack teeth and feed by sucking in crustaceans, small fish, jellies, and squid. Their vacuum-feeding lifestyle is aided by their protrusible jaws, which improve the strength and directionality of suction-feeding. (For amazing videos of how protrusible jaws are used in suction-feeding, visit the Wainwright Lab's YouTube Channel).
 |
| (*Click to embiggen*) This shows R. glesne; R. russelii looks very similar. From the LA Times (2010) |
The oarfish's skin contains guanine crystals, which reflect light and give them an iridescent silver color. Their color and incredible size have earned them the common name "King of Herrings".
Living oarfishes are pelagic, inhabiting open water away from land. Some ichthyologists believe they live at considerable depths and only enter shallow water when they are stressed. Others believe that they live in upper layers of the ocean, but are far enough offshore that they are only observed by humans when they drift nearer to shore. The eyes of the Catalina oarfish are being examined by ichthyologists to answer this question -- if the eyes show evolutionary adaptations for seeing in low-light, then it's more likely that they live at great depths, where sunlight is very dim.
All oarfish specimens studied so far appear to have lost part of their tail. Ichthyologists do not think that the tails are bitten off but rather that, like lizards, the can fish drop their tails (called autotomy) and re-grow them. It is an open question if oarfish autotomize their tail to escape predators (as lizards do) or to save energy.
Scientists don't know much about what eats oarfishes; many resources indicate that nothing eats them. However, a study of parasites in the Catalina oarfish suggests that sharks might be an important predator. The specimen found on Catalina carried immature tapeworms that, as adults, are found in sharks. Scientists hypothesize that the tapeworm completes its lifecycle by passing to sharks after they eat an oarfish.
 |
| Image from Strangesounds.org |
Imagine that you are sailing on a tall-ship in the 17th century. Let's say that you haven't seen land in several months. Most likely, you are malnourished and have scurvy. You're tired because you're on watch every four hours - sleeping for less than four hours between watches. You are a good sailor, but you lack any formal education. You live your life on the ocean, but you can't swim. Falling into the water is a death sentence.
One early morning, just as the sky is lightening, you catch a glimpse of a silvery snake-like animal off the port bow. It's big -- maybe 30 feet long -- with large red appendages projecting from its head. It has big eyes and a strange way of swimming. It is there and gone before you can summon a fellow sailor. You walk away from the rail, not sure of what you just saw.
What would you make of your glimpse of an oarfish? Calling it a "sea serpent" seems pretty reasonable - and oarfish are probably the source of many sea serpent legends that filled the imaginations of sailors and landlubbers alike.
In Japanese folklore, the slender oarfish is known as the "Messenger from the Sea God's Palace" because its arrival portends a coming earthquake. Just before the Fukushima earthquake in 2011, 20 oarfish washed ashore in Japan.
However, there doesn't appear to be an association between oarfish strandings and earthquakes: the appearance of oarfish in California were not followed by any extraordinary seismic activity. For example, no significant earthquakes followed strandings in 1997 (Coronado), 2006 (Catalina), or last fall.
More information about oarfishes
Want to see some cool pics of oarfishes? Two sites to check out are:
- Photo gallery from the LA Times
- Video of swimming/feeding oarfish (by the SERPENT Project)
Sources
Thank you to Russ Vetter at NOAA and Rick Feeney at the Natural History Museum of LA County for answering my questions about which species washed ashore.
Bloomekatz, A. and T. Barboza. 16 October 2013. Giant oarfish carcass off Catalina among the biggest in recent years. The LA Times.
Schaefer, S. 21 October 2013. Giant oarfish carcass found off Catalina to be split for research. The LA Times.
Schaefer, S. 22 October 2013. Giant oarfish likely carried ashore by ocean current, scientist says. The LA Times.
Schaefer, S. 29 October 2013. Oarfish hosted parasites, giving scientists insight into bony fish. The LA Times.
FishBase entries for oarfish order, family, and species.
Quenqua, D. 2 November 2013. Oarfish offers chance to study an elusive animal long thought a monster. The NY Times.
Graphic of the Giant oarfish originally appeared in the LA Times, but was downloaded from a story in the UK Daily Mail.
No comments:
Post a Comment