Once again a day aboard the King Neptune and a dive on the sandy bottom habitat between the inner and outer reefs at Hen Rock provided an unexpected film opportunity. I had descended with the thought of looking for the orangethroat pikeblennies I've seen here. As is often the case, my dive "plan" changed when I encountered a fish I've seen only rarely in our waters and had filmed only off La Jolla... the bay pipefish.
Pipefish are relatives of the seahorses. They differ in that their bodies look like they were seahorses that participated unwillingly in the Spanish Inquisition. I'm referring to my impression that the body appears to have been stretched out as one would expect from a day on the torture device known as "the rack." Of course evolution doesn't work this way, but I think you get the idea. I believe the individual I found is the bay pipefish, one of several species known from California waters. Their long, slender bodies (Twiggy would be jealous) generally are 4-7 inches in length but large individuals like the one I spotted may reach over a foot.
Five species of pipefish are found in southern California. Bay pipefish may be observed in varying shades of green to brown with patches or bellies that are white. Since at least four of the pipefish species are very similar, body color alone is not sufficient to tell them apart. In fact, the bay pipefish was thought by some biologists to be a subspecies of the kelp pipefish until a 1980 study confirmed their uniqueness as a species. The only real way to tell the species apart is by close examination of the body and tail rings, and the number of rays in their fins. A bit too tedious for me to undertake!
Their habitat is another way to gain a clue as to the species' identity. Barcheek pipefish usually are found in floating seaweed along the coast. The barred pipefish is more common in the eelgrass beds of shallow bays. The kelp pipefish is found, as its name suggests, in kelp forests. It is the one I've seen in our waters in years past, before I had a video camera. The bay pipefish prefers shallow eelgrass and algal beds. Its depth range is listed in one book as 0-30 feet, but the one I filmed was in excess of 40 feet (obviously an individual of greater "depth" than his more "shallow" friends).
Bay pipefish are found from Alaska (brrr) through southern California and down to southern Baja. It is the only pipefish species found from Oregon north. Their tolerance for cold water is obviously much higher than mine! According to my research, the bay pipefish can also tolerate estuaries where water is lower in salinity than in the ocean.
As for munching, once it acclimated to my presence, I was able to observe this individual hunting and feeding. It would swim very slowly and very close to the sandy bottom looking for small invertebrates, mainly bottom-dwelling crustaceans or zooplankton, to feed on. Its scientific name "Syngnathus" means slender snout. As it approached a potential meal, I noted it turned its head sideways before striking. Because its eyes are on either side of a long head and mouth, I assumed it was turning its head to allow for a better look. If it decided the snack was worth it, the pipefish quickly opened its tubular mouth and sucked the prey inside like a vacuum cleaner.
Mating in pipefish and seahorses is interesting. As some of you may know, the male is the gender that protects the eggs and does the babysitting. I wonder why females are so smart in so many fish species. Although some studies suggest spawning occurs from May to August, another seems to suggest February through November. There is some evidence to suggest males may accept the eggs of several females into their brooding pouches. Depending on the water temperature, the eggs may take 1-3 weeks to develop into larvae and are released as free-swimming juvenile fish.
A study by Wilson earlier this year indicates that pipefish may mate with members of another pipefish species where they exist together based on analysis of the fertilized eggs in male brood pouches. This means that no mechanisms have evolved yet to prevent mating and fertilization. I guess the pipefish, unlike scientists, have trouble counting their own fin rays and body rings. However, no adult hybrids between the two species were observed so it is probable that these cross-fertilized eggs do not survive their early life stages.
Although they are said to be wary of divers, I found this one could be approached closely if I proceeded slowly. After a few minutes it got accustomed to my presence and continued its activities, including feeding. It even allowed me to gently pick it up for closer views of the small, pointed head and fan-shaped tail. I spent an enjoyable half hour with this unexpected find.
These small and very slender fish have no real commercial or sport value. Filet of pipefish would look like a small ribbon and even a hundred of them would hardly satisfy my appetite. However, my Internet research revealed that some species of pipefish are dried and used for medicinals by the Chinese.
© 2006 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays. Please help me climb out of self-imposed poverty... buy my "Munching and Mating in the Macrocystis," "Great White Sharks of Guadalupe," "Calimari Concupiscence: Mating Squid, " "Playful Pinnipeds: California Sea Lions," "Belize It or Not: Western Caribbean Invertebrates, Fish and Turtles" or "Gentle Giants: Giant Sea Bass" DVD's. Yes, take Dr. Bill home with you... we'll both be glad you did!
Pipefish feeding over sandy bottom; turning on side
to inspect potential prey,
fan shaped tail.
This document maintained by
Dr. Bill Bushing.
Material and images © 2006 Star Thrower Educational Multimedia