Tag: Camm Swift

Biologists tentatively ID mystery L.A. River bass

Our mystery bass. (Roland Trevino)
Our mystery bass. (Roland Trevino)
Another view of the mystery bass. (Roland Trevino)
Another view of the mystery bass. (Roland Trevino)

One of the best parts of fishing our river is you never know what you’re going to pull out of it. In the old days, this comment would elicit some snark about a “really brown trout,” haha. But today, we discuss what in the heck are these crazy bass that Roland Trevino pulled from one section?

Take a look at his pics and see how white the sides are.

Rosi Dagit, Senior Conservation Biologist and Certified Arborist for the Resource Conservation District of the Santa Monica Mountains, agreed that they were “strange-looking bass” because “the white-side blotches are quite noticeable” in the pics we showed her.

She enlisted the help of Camm Swift, emeritus PhD from the Natural History Museum of Los Angeles.

“These appear to be very faded out largemouth bass, but it would be good to see both dorsal fins elevated. Maybe they came from fairly turbid water,or were held in a white bucket for a time and lost lots of color?” he wrote in an email to Dagit.  “There is a slight possibility they are white bass or white perch, Morone chrysops or M. americanus, but they have much larger anal fin spines than largemouth bass and do not appear to be present in these fish.

“Both of these species are from the eastern United States (as are largemouth bass for that matter!) and the white bass is known from a few places in central California but unlikely in L. A.   Thus, without some other convincing evidence I would call them largemouth bass.”

Swift also offered some advice on how to help the experts positively ID a mystery fish.
“If it’s hard to keep the fish, a good photograph from the side with the fins spread is useful to get close, anyhow.  Putting them in a water-filled Ziploc or one of those small plexiglass boxes like fish photographers use can suffice.  Usually the fish will expand its fins when swimming or resting in  one of those.”
For my part, I’m still not so sure. If anyone catches another white mystery bass, let’s get a better shot and see what the biologists say.
See you on the river, Jim Burns