How to Identify Donderpad

To identify Donderpad (Cottus perifretum), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Variable, typically mottled brown, grey, and olive green, providing excellent camouflage. Underside is usually paler, whitish to yellowish. Fins often have dark bands or spots.

Scale type

none

Mouth position

terminal

Distinctive features

Large, flattened head with a wide mouth, Absence of scales, skin is smooth or covered with small prickles, Large, fan-like pectoral fins, Two dorsal fins, the first spiny and the second soft-rayed, Preopercular spine present, typically blunt or slightly pointed

Dorsal fin

Two dorsal fins: D1 (spiny) with 6-9 rays; D2 (soft-rayed) with 16-20 rays. The two fins are typically separated or barely touching.

Tail fin

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

Pectoral fin

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

Distinctive fins

Pelvic fins are thoracic, located beneath the pectoral fins, with 1 spine and 3-4 soft rays. Anal fin has 11-15 soft rays.

Identification Tips

1. 1

   Head Shape

   Look for a distinctly flattened and broad head, wider than the body.

2. 2

   Pectoral Fins

   Observe the large, fan-like pectoral fins that are characteristic of sculpins and extend well past the anal fin origin.

3. 3

   Scales

   Confirm the absence of scales; the skin will appear smooth or have small, embedded prickles, unlike many other freshwater fish.

4. 4

   Dorsal Fins

   Note the presence of two distinct dorsal fins, the first spiny and the second soft-rayed, usually separated.

5. 5

   Coloration

   Its mottled brown/grey/olive coloration provides excellent camouflage against stony riverbeds.

Explore Donderpad