Dive Dry with Dr. Bill

#390: The Pile Surfperch

Common names for critters are often confusing. More than one species may have the same common name, as in black sea bass for our local species (now referred to as the giant sea bass), and another on the East Coast. A single species may have several common names as is the case with the topic of today's column, the pile surfperch. They are also referred to as the pile seaperch and the dusky sea-perch. This is one reason why species are given one scientific name (you know, that Latin and Greek stuff) to avoid confusion... well at least for scientists but probably not the average diver or angler!

However, in the case of the pile surfperch even the scientists seem a bit confused! Harvard's Louis Agassiz first described this species scientifically back in the 1850s and placed them in the "ragged lip" genus, Rhacochilus with the species name vacca. Experts including Dr. Milton Love and Dr. Dan Gotshall list it under the name Damalichthys vacca which it acquired later. Other researchers believe that the original name should be the currently accepted one. Yes, scientific names change as we gain new understanding of species based on things like DNA. It would be much easier on all of us if we just called each individual pile surfperch by their real names... Mary, Ted, Alice and Bob.

Pile surfperch are usually a silvery gray, occasionally with dark blotches. A dark bar down the side below the dorsal fin is a distinctive feature although it tends to be more obvious in juveniles than adults. Another distinctive feature is a small black spot behind the mouth. The spiny front dorsal fin is lower than the soft dorsal fin behind it. These surfperch have a deeply forked tail or caudal fin. Similar species include their close relative, the rubberlip seaperch which has more pronounced lips, and the sargo, a sea chub, whose bar is located further back on the body and has a taller front than rear dorsal fin. The pile surfperch is usually in the six to fourteen inch range, but they may exceed seventeen inches. Last weekend I was diving Santa Cruz Island with the Roddenberry Dive Team and saw some of the largest pile surfperch I've ever seen... must have been the higher productivity in those colder, nutrient rich waters... or a case of steroid use!

Pile surfperch are known from Port Wrangell, AK, south to northern Baja California and Guadalupe Island. Although reported to a maximum depth of 690 feet, they usually stay shallower than about 60 feet so they are easier to spot by us divers! How courteous of them. Reefs, kelp beds, piers and oil platforms are their preferred residences, but they may also be seen in shallow bays. Off Redondo Beach they are said to move into shallower bays during winter and spring.

These surfperch are active during the day. They fed as "pickers" rather than "winnowers" on the bottom, selecting out individual prey species rather than taking a huge mouthful, sorting out the munchies and spitting out the debris like their relative the rubberlip seaperch. Menu items include mussels, snails, crabs, barnacles and brittle stars. They will also take mud shrimp and tube dwelling crustaceans known as amphipods. When feeding on snails known as wentletraps, their mouths may turn purple! These mostly hard-shelled "goodies" are crushed in the throat using plates containing molar-like "teeth." In the Mutual Eating Society, what eats usually gets eaten. Harbor seals, northern elephant seals and cormorants are usually assigned this task. These fish were also eaten by Native Americans, and are an important target for recreational anglers. However, the commercial take of them is a paltry 200 pounds a year, making this yet another species where the recreational take has far greater impact on a fish than the commercial harvest.

Pile surfperch are usually sexually mature in their second year at about seven inches in length. Imagine combining the "terrible twos" with the raging hormones of junior high students! Spawning initiates in April in the warmer waters of southern California, but is delayed until May in the colder waters off Oregon. When courting, the males often turn dark (after all, "black is beautiful"). They leave the protection of the kelp and hang head down in midwater exposed to potential predators. What we men won't do for love. Maybe Cal Worthington has a point when he says he'll "stand on my head" to make you a better deal! When a lady approaches, the male will initiate a courtship dance. Fortunately they are better than those of my species and don't step on their romantic partner's fins. The male may try to tend several females since polygamy is allowed "down under," and he will chase competing males away.

All surfperch are live bearers, requiring internal fertilization. The ladies carry the young throughout their development stages. The female's gestation period appears subject to some uncertainty. Scientists variously report it as 6 1/2 to 15 months. The confusion may in part be due to the fact that females may mate, but not actually fertilize their eggs with the stored sperm until several months later. Certainly makes paternity an interesting question! The young are born between late June and early August which supports the longer gestation time. Dr. Milton Love indicates litter sizes of up to 50 young, while another source states only three to ten are born at a time. Maybe it depends on their intake of fertility drugs that find their way into our oceans through human urination and the sewage system. Human birth control chemicals are known to follow this path, and affect conception in various marine species in our waters to the south of Point Conception and elsewhere (that was just for humor's sake... you did laugh, right?)!

© 2010 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 and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Pile surfperch swimming through kelp and "picking" food on the bottom;
and the somewhat similar looking sargo and rubberlip seaperch.

This document maintained by Dr. Bill Bushing.
Material and images © 2010 Star Thrower Educational Multimedia