Finescale Triggerfish (Balistes polylepis) held by Chris Starbird. He discovered it on 26 October 2012 in some oyster gear in Tomales Bay (near Marshall).
Chris recognized this as an unusual find. Finescale Triggerfish are subtropical species. Although their range is listed as Point St. George (Del Norte County) to Peru, they're rare everywhere in California, especially north of Point Conception (range information from California Department of Fish and Game).
Below is a picture of Chris holding the fish (photo by Nicki Vogel). In both photos, look for the following features (on the fish, not Chris!):
- strongly compressed body
- plate-like scales
- overall olive-brown to gray coloration, with hints of blue
- anterior dorsal fin with 3 spines
- only 1 gill slit (the vertical line just in front of the pectoral fin)- small mouth with protruding teeth (used for crushing invertebrates such as sea urchins, crustaceans, and molluscs)
It's hard to know how this fish made it to Tomales Bay, but they may accompany warm water intrusions along the coast. There's been some debate about whether this will be a strong El Niño year, but warm water anomalies have been recorded during the past few months.
I've been having trouble finding anyone who has seen a triggerfish in this area before. If you have or know someone who has, I'd love to hear about other local triggerfish sightings (this year or in the past).
And keep an eye out for other species that signal possible warm water influxes!
Great find, Chris! And thanks to Chris and Vicki for their generosity in sharing these photos and this intriguing story.