Marbled Sculpin

Marbled sculpins, like other sculpin species, have a large, flat head and large, fan-like pectoral fins. They have a striking mottled coloration with patches of black and various shades of brown. In Inland Fishes of California (2002), Peter Moyle describes their physical characteristics as follows: "Marbled sculpins can be distinguished by the following suite of characteristics: 7-8 dorsal fin spines, broadly joined dorsal fins, incomplete lateral line with 15-28 pores, smooth skin (except for a small patch of prickles in some populations), 2 chin pores, absent palatine teeth, and only 1 well-developed preopercular spine (although one or two inconspicuous protruberances [sic] may be present below it) (1). In addition they have a wide head, with widely separated eyes, a blunt snout, a maxillary bone that does not reach the posterior edge of the eye, and usually no conspicuous dark patch on the rear portion of the first dorsal, although a band may run across most of the fin. There are 7-8 spines in the first dorsal fin, 18-22 rays in the second dorsal fin, 13-15 anal fin rays, 14-16 pectoral fin rays, and 11-12 principal rays in the caudal fin. The pelvic fins have four "elements" and may or may not reach the vent when depressed. Prickling may be well developed on young fish but is confined to a small region behind the pectoral fins in adults or is absent. …

Moyle states that the lower Klamath marbled sculpin occurs in the mainstem Klamath River and its tributaries from the Trinity River confluence up to Iron Gate Dam, and that the upper Klamath marbled sculpin inhabits the watershed upstream of Klamath Falls. However, it is likely that this species has also been present in tributaries to the Klamath River between Iron Gate Dam and Klamath Falls. With the removal of four Klamath dams in 2024, populations downstream of the Iron Gate Dam site will now be connected to further upstream populations for the first time since 1918. Surveys of the Lost River watershed in the upper Klamath basin found marbled sculpin to only be occupying a few small headwater streams. Bigeye marbled sculpin are found in the lower Pit River watershed, including tributaries such as Hat Creek, Burney Creek and the Fall River.

Habitat preference. Bigeye marbled sculpin prefer run or pool habitat, with fine substrate capable of supporting aquatic plants. They are often found in deeper areas of a habitat next to cover features such as aquatic vegetation. A study of the thermal tolerances of the three species found that C.k. macrops preferred temperatures ranging from 11.1 to 14.7 °C (52.0 to 58.5 °F), and extended exposure to temperatures above 25 °C (77 °F) was shown to be lethal. Regarding C.k. …