Page 8 - bell1978fishes

8 CONTRIBUTIONS IN SCIENCE No. 295

Gambusia affinis (Baird and Girard) Mosquitofish (24)

Catostomus (Pantosteus) santaanae (Snyder) Santa Ana sucker (20)

Pimephales promelas Rafinesque Fathead minnow (15)

Salmo gairdneri Richardson Rainbow trout (5)

Lepomis cyanellus Rafinesque Green sunfish (6)

Micropterus salmoides (Lacepede) Largemouth bass ( 4)

I ctalurus punctatus (Rafinesque) Channel Catfish ( l)

Cottits asper Richardson Prickly sculpin (3)

Notemigonus crysoleucas (Mitchill) Golden shiner ( 1)

Dorosoma petenense (Gunther) Threadfin shad (1)

Eu.cyclogobius newberryi (Girard) Tidewater goby (1)

Leptocottus armatus Girard Pacific staghorn sculpin (1)

Lampertra triderzteta (Gairdner) Pacific lamprey (2)

Fish collection records are summarized in Table 2 and the locations of collection

stations are shown in figure 1.

Gasterosteus acculeatits occurred in every stream where fishes were found except

in Arrastre Canyon and Castaic Creek. It was abundant at all stations where it occurred

except in the Santa Clara River between Saugus and Piru and in the headwaters of

some tributaries. This species was collected by J. N. Baskin (personal communication)

at my station F, farther upstream in San Francisq uito Canyon than I was able to find

•
It.

Gila orcutti penetrates farther into headwaters than Gasterosteus. In addition to

being widespread in the Santa Clara River and all tributaries in which fishes were

found, it was observed in Arrastre Canyon (stat. G) and farther up San Francisquito

Canyon (stat. F), Sespe Creek (stat. D) and Piru Creek (stats. 43, 44, E) than

Gasterosteus.

Gambusia affinis, Catostomits santaana.e and Pimephales promelas are all wide-

spread in the Santa Clara River but are restricted in some tributaries. Gambusia affinis

apparently is absent above station 22 in the upper Santa Clara River and was not found

above station 30 in Sespe Creek or station 39 in Piru Creek. Generally the absence

of Gambitsia is associated with an increase in stream gradient (Table l). Catostomus

santaanae was absent from small tributaries like Todd Barranca, San Francisq uito

Canyon and Arrastre Canyon and also from the headwaters of Sespe Creek (above

stat. 32). However, J. N. Baskin (personal communication) found it and Gila orcutti

in isolated pools in Mill Canyon, which joins the Santa Clara River near station 23.

Pimephales promelas has a more restricted distribution. In the Santa Clara River, 'it

occurred below station 14 and has only entered the lower gradient portions of Sespe

Creek, below station 30. However, fathead minnows were seen above Lake Piru and

were collected in the lake, in two stations downstream in Piru Creek and below Castaic

Lake.

The only other widespread species is Lepomis cyanellus, which was taken at six

disjunct stations in the Santa Clara River, Todd Barranca, Castaic Creek and seen in

Sespe Creek. It probably occurs elsewhere, but may be rare and difficult to collect.

Other species found in the system are either locally abundant or associated with

unusual conditions. Salmo gairdneri lives in the discharge of Fillmore Fish Hatchery