Dive Dry with Dr. Bill

#383: A Perch I Could Take a Shine To

The past week or so I've been focused on editing the first of three proposed cable TV episodes on the surfperch family. I just finished the first, and have to take a break from editing video so I can write this week's column... and do my (ugh) income taxes. The only good thing is I'm quite sure I didn't have enough income to pay taxes... but that's also the bad thing. And for all those learned economists out there, a good ecologist (or even Dr. Bill) could have told you based on the theory of food web stability that being "too big to fail" is a non-starter in the natural world. And thanks to my grandfather and parents, I learned early not to leverage. Maybe we should train our economists in sound ecological theory rather than "economy" because now there seems to be little of that left. I have been fortunate in having friends such as Matt and Nadja who have enjoyed these columns so much, they've contributed air fill cards to keep it coming. Yes, I digressed once again. So what... you're not paying to read this so you'll have to live with my "occasional" mental meanderings and senior moments! On to this week's subject.

My focus today will be the shiner surfperch (Cymatogaster aggregata). This poor fish must be very confused since it has been given so many other common names by human beings: the Leven perch, pogie, seven-eleven, yellow shiner, bay perch and sparada. My psychiatrist would probably have a lifetime of work just trying to sort out this fish's multiple personalities. The first fossil evidence of this species dates back a million years into the Pliocene... but of course I was not yet diving then. To make matters worse, we marine biologists have disagreed on whether the individuals found off the northern Channel Islands are of this species, or a distinct one referred to as the island surfperch. As for their scientific name, Cymatogaster, is from the Greek for "fetus belly" and aggregata from the Latin for "crowded together," referring to their schooling behavior.

The surfperch family is a group endemic to the West Coast of North America. My regular readers know this means they are only found there. My irregular readers probably take laxatives. This species may be the most common surfperch in California waters, and I certainly see plenty of them in our dive park. They normally range from three to six inches in length, and the maximum reported size is between seven and eight inches. Their body color is generally described as silver, but I often see it as golden in color and others have described some as gray to greenish. I prefer silver or gold... since it at least makes me feel I am rich while underwater. Small black spots on their scales form thin horizontal stripes along the side, and there are usually three (sometimes two) yellow bars running vertically mid-body. These three bars often look like the numbers 7-11 and are the reason for that common name.

Shiners are known from Port Wrangell, Alaska, to San Quintin Bay and Guadalupe Island in Baja California, Mexico. They are abundant from British Columbia to southern California, but rarer in the northern and southern ends of their geographic range. Their preferred habitats are wide ranging: shallow, quiet bays; eelgrass beds; kelp forests; soft bottoms and manmade structures such as piers, jetties and oil platforms. Their most desirable depth range is down to about 50 feet, but they have been taken as deep as 690 feet. In some parts of their range, these surfperch will enter shallow water during the spring and return to deeper waters in the fall. This may be to take advantage of warmer water in spring when they mate, and to avoid storms during winter.

Their upward slanting mouth is well designed for feeding as a "picker." Some surfperch "pick" food off of algae like kelp, the rocky reef, the sandy bottom or from the plankton drifting around them. Others are "winnowers," sucking "big gulps" of turf into their mouths, sorting out the inedibles from the edibles in their throat, and then spitting out the non-nutritive debris. They are often very messy feeders, while the pickers are more dainty in their approach. Feeding in this species occurs mainly during the day. Preferred items on the shiner surfperch's menu include fish eggs and a wide variety of small invertebrates including plankton such as copepods, amphipods, mysids, isopods, crab larvae and arrow worms as well as small "clams" and worms. Yummy! In turn they are munched on by kelp bass, barred sand bass, California halibut, harbor seals, sea lions, great blue heron, western gulls, least terns, Brandt's and double crested cormorants. Good thing they are so abundant as they have a lot of mouths to feed!

Speaking of mouths to feed, these surfperch (like the rest of the family) give live birth. Here in SoCal they are reported to mate as early as April and as late as July. Because they give live birth, fertilization must be internal since the female carries the young inside. Male surfperch have enlarged regions, sometimes referred to as "nipples," at the front of their anal fins which facilitate actual mating. Males are quite precocious, becoming sexually mature soon after birth. Of course sperm production does not require the large body size necessary in females to produce eggs and carry young. The girls generally aren't reproductively mature for a year, but even they can be inseminated soon after birth because sperm may be stored as long as six months and they may carry the young for as long as a year before giving birth.

During breeding season the stripes on the male may darken and the yellow bars seem to fade a bit. They seek out females of roughly their own size, and do what some male humans are less likely to do... perform a "dance" to attract their mate. The male will follow closely behind the female, and the dance may be quite well choreographed. He will occasionally leave her to chase off other males, a ritual I've seen performed at the Chi Chi Club by a totally unrelated species of male. Younger females give birth to litters of about five young, while older (and larger) females may have 20 to 36 little ones. Fortunately, my son Kevin and daughter-in-law Mary only expect one child next month... or I might become an octo-grandpa!

Hard to believe that these small fish may be the species most frequently caught by young anglers in our State. I don't remember seeing them taken off the Pleasure Pier or Cabrillo Mole. This may be because their very small mouths require tiny hooks and most anglers are going after something a bit larger in size! They are also taken occasionally for bait when fishing for halibut or bass. A small commercial fishery for them nets a mere 600 pounds a year. The surfperch are yet another example of where the recreational fishery has far more impact on the species than the commercial guys (and gals). Of course given their large numbers, this particular species does not appear to be threatened at all.

© 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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Silver colored shiner surfperch (courtesy of Kevin Lee), the 7-11 surfperch; "surf" perch doing what it does best
and more golden looking shiners in the Casino Point dive park.

This document maintained by Dr. Bill Bushing.
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