How to Identify Northern Puffer

To identify Northern Puffer (Sphoeroides maculatus), look at these key features.

Physical Characteristics

Body shape

rounded

Coloration

Dorsal surface is typically olive-green to brownish-gray, often mottled with darker spots and blotches. The ventral surface is white to pale yellow. A distinctive row of dark spots or bars is often present along the sides, and a dark bar is usually present between the eyes.

Scale type

none

Mouth position

terminal

Distinctive features

Ability to inflate body into a spherical shape when threatened., Small, spiny prickles on the belly, particularly noticeable when inflated., Absence of pelvic fins., Beak-like mouth with fused teeth.

Dorsal fin

Single, small dorsal fin located far back on the body, typically with 10-12 soft rays.

Tail fin

Rounded caudal fin.

Pectoral fin

Small, rounded pectoral fins located behind the gill openings.

Distinctive fins

No pelvic fins. Anal fin is small and similar in shape and position to the dorsal fin, with 9-11 soft rays.

Identification Tips

1. 1

   Body Shape

   When not inflated, the body is somewhat elongated and club-shaped. When threatened, it rapidly inflates into a sphere.

2. 2

   Coloration and Markings

   Olive to brownish-gray back with darker spots and blotches, white belly. Look for the dark bar between the eyes and the row of dark spots along the lower sides.

3. 3

   Spines

   Small, retractable spines are present on the belly, which become erect when the fish inflates.

4. 4

   Fins

   Absence of pelvic fins is a key characteristic. Dorsal and anal fins are small and set far back on the body.

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