Dive Dry with Dr. Bill

#700: Benny the Blenny Bites

Hard to believe, but this is my 700th "Dive Dry with Dr. Bill" newspaper column. I must have started back when I was 12 years old! No one can say this old geezer doesn't have fortitude... or, perhaps, the need to earn enough $$$ for food in retirement. Social Security just doesn't cut it. Better than being a Walmart greeter... especially since there isn't one on our island! To celebrate this milestone, I thought I'd write about a critter I have never seen before in our waters.

A few weekends ago I was ascending toward the dive park stairs to exit when my eye caught sight of a fish I didn't recognize. It must have recognized me though as it furiously began darting out from its shelter hole and trying to bite me. It succeeded twice. No, it wasn't a male garibaldi defending its nest of freshly laid eggs. However, I wasn't sure just what it was!

I took 13 minutes of raw video on two dives that first day. Due to its erratic movements interspersed with hiding in the shade of a tight shelter hole, I was only able to extract four decent still images. I sent these off to the fishiest person I know, Dr. Milton Love, a colleague from our early Jean-Michel Cousteau Project Ocean Search days back in the 1970s and with whom I have co-written a paper on the first documented appearance of the whitetail gregory or damsel (Stegastes leucorus) in California waters. Milton is the author of the best fish guide for our waters, the 650 page tome entitled Certainly More Than You Want to Know About the Fishes of the Pacific Coast.

I had tentatively identified the fish as a largemouth blenny (Labrosomus xanti), formerly known only as far north as Guadalupe Island off Baja but recently sighted in San Diego waters as another El Niño "intruder." Milton wrote back that it could indeed be that species, but it could also be the related multipore blenny ( Labrisomus multiporosus). The diagnostic characteristics are difficult to see in a photograph so accurate identification would require a specimen. Since the dive park is a marine protected area and a no take zone, that was not possible.

Assuming it is the largemouth blenny, it was hard to find good references to research it since it only recently entered US waters. Fortunately I have a field guide for Mexican fish and thanks to my classmate Al Gore, I have the Internet! After all, he did invent it... didn't he... NOT! South of the border they call this fish chalapo.

This fish is relatively small with a maximum reported length of about seven inches. It tends to be a greenish brown although the stills I took during daylight made it look reddish brown. It has about eight dark bars along the side and numerous small white spots on the head and body. The two dorsal fins are slightly separated and there is usually a dark spot at the front of the first dorsal. There are bristles or cirri present on the nostrils and above the eye.

The largemouth frequents shallow water, usually no deeper than about 30 feet. It prefers rocky shores with algal covering. They are found from Guadalupe Island down into the central Gulf of California (Sea of Cortez) and from there south to the Revillagigedos (Socorro) Islands and just north of Acapulco on the mainland coast of Mexico.

Although one source claimed they were nocturnal feeders, on a recent night dive I found this one sheltering deep in his rocky lair and acting quite shy compared to its highly aggressive behavior during the day (see band aid on my finger). However, in researching for this column, most sources stated it is a daytime (diurnal) feeder that chows down on crustaceans such as shrimp and crab.

The males are highly territorial as indicated by its aggressive daytime behavior. It is reported that the female lays her eggs in protected nooks and crannies. This individual may have been defending eggs as well as its territory although I didn't see any. The red-orange coloration of the head suggests the one I saw was a male in breeding coloration. If so, there must be other blennies in the dive park to mate with. Instructor Ruth Harris and Janna Nichols, outreach coordinator for REEF, both told me they had seen other largemouth blennies in the park. On subsequent dives I've found at least four or five more, most appearing to be female.

The blennies in this fish family are somewhat difficult to tell apart, hence Milton Love's suggestion of the need for an actual specimen to authenticate the identification. The largemouth is the most common of the members so the odds are in my favor. One website I researched stated that these blennies are of limited interest due to their small sizes. I should sick Randy "Short People" Newman on that site's author!

On my final weekend of diving before entering Torrance Memorial Hospital, dive buddy Catherine Ngo came out to spend the weekend submerging with me. We succeeded in finding three giant sea bass, the first she had ever seen. However, I was only able to show her the one male blenny as the ladies all seemed to be in hiding. She played bait by wiggling her fingers in front of him so he would burst out and bite them to demonstrate his aggression. It wasn't a full moon so I didn't try to bite her. Catherine decided he needed a simpler name than Labrosomus xanti and decided he should be known forever more as Bennett or "Benny" the Blenny. So be it! Maybe Milton Love will include that name in the next edition of his fish guide!

© 2016 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). 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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Male largemouth blenny (top), female blenny and Catherine's fingers enticing the male to attack.

This document maintained by Dr. Bill Bushing.
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