How to Identify Coastrange Sculpin

To identify Coastrange Sculpin (Cottus aleuticus), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Variable, typically mottled brown, gray, or olive on the dorsal surface, with irregular dark blotches and saddles that provide camouflage. The ventral surface is usually paler, often whitish or yellowish. Fins are often banded or spotted.

Scale type

none

Mouth position

terminal

Distinctive features

Large, broad head that is flattened dorsally, Large, fan-like pectoral fins, Two dorsal fins, the first spiny and the second soft-rayed, Absence of scales, body covered in small prickles (spinules) which can be more or less developed depending on population and age, Preopercular spine typically simple and sharp, not branched

Dorsal fin

Two dorsal fins; the first with 7-10 spines, the second with 16-20 soft rays. The two fins are typically separated or barely joined.

Tail fin

Caudal fin is rounded or slightly truncate, with 11-13 rays.

Pectoral fin

Large and fan-like, with 13-16 rays, extending beyond the origin of the anal fin.

Distinctive fins

Pelvic fins are thoracic, with one spine and 3-4 soft rays.

Identification Tips

1. 1

   Body Prickles

   Examine the skin for small, embedded prickles (spinules). While all sculpins lack true scales, the extent and distribution of these prickles can vary and help differentiate species. Coastrange Sculpin typically has prickles covering most of its body, though they can be sparse in some individuals.

2. 2

   Preopercular Spine

   Carefully observe the spine on the preopercle (bone just in front of the gill cover). In Cottus aleuticus, this spine is usually simple, sharp, and unbranched, pointing posteriorly. This distinguishes it from some other sculpin species that may have branched or blunt spines.

3. 3

   Dorsal Fin Separation

   Note the separation between the first (spiny) and second (soft-rayed) dorsal fins. In Coastrange Sculpin, these fins are typically distinctly separated or only barely joined at their bases, unlike some other sculpins where they may be broadly joined.

4. 4

   Pectoral Fin Length

   The pectoral fins are notably large and fan-like, often extending posteriorly beyond the origin of the anal fin. This is a good general characteristic for sculpins but can be used in conjunction with other features for species-level identification.

5. 5

   Head Shape

   The head is broad and flattened, giving it a somewhat triangular appearance when viewed from above. This is a common sculpin trait but contributes to its overall cryptic morphology.

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