How to Identify Grubby Sculpin

To identify Grubby Sculpin (Myoxocephalus aenaeus), look at these key features.

Physical Characteristics

Body shape

rounded

Coloration

Highly variable, typically mottled brown, olive, or reddish-brown with darker blotches and bands, providing excellent 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 with a wide mouth, Two dorsal fins, the first spiny and the second soft-rayed, Prominent, fan-like pectoral fins, Absence of scales, body covered in small prickles or tubercles, giving a 'grubby' feel, Preopercular spine: typically 4 spines on the preopercle, with the uppermost being the longest and often curved upwards., Lateral line: complete and typically armed with bony plates or tubercles.

Dorsal fin

Two dorsal fins: D1 (spiny) with 7-10 spines; D2 (soft-rayed) with 12-16 rays. The first dorsal fin is typically lower than the second.

Tail fin

Caudal fin is rounded or slightly truncate, with 10-12 rays.

Pectoral fin

Large and fan-like, with 15-18 rays, extending beyond the origin of the anal fin.

Distinctive fins

Pelvic fins are small, thoracic, with 1 spine and 3 rays. Anal fin has 10-13 soft rays.

Identification Tips

1. 1

   Body Texture

   Feel for the rough, prickly skin (absence of true scales) which gives it its common name 'grubby'.

2. 2

   Preopercular Spines

   Count the four preopercular spines; the uppermost is typically the longest and often curved upwards, a key distinguishing feature from some other sculpin species.

3. 3

   Dorsal Fin Height

   Note that the first (spiny) dorsal fin is generally lower than the second (soft-rayed) dorsal fin.

4. 4

   Pectoral Fins

   Observe the large, fan-like pectoral fins that often extend past the origin of the anal fin.

5. 5

   Coloration and Pattern

   Look for the mottled brown, olive, or reddish-brown coloration with darker blotches, which provides excellent camouflage against rocky substrates.

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