How to Identify Penguin Tetra

To identify Penguin Tetra (Thayeria boehlkei), look at these key features.

Physical Characteristics

Body shape

torpedo

Coloration

Silvery body with a prominent, straight black stripe extending from the operculum to the caudal peduncle, continuing diagonally into the lower lobe of the caudal fin. Fins are generally hyaline (transparent), though some individuals may show a faint yellowish tint.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Black stripe extending into the lower caudal fin lobe, Characteristic head-up swimming posture, Small adipose fin

Dorsal fin

Single, relatively small dorsal fin located mid-body.

Tail fin

Forked caudal fin, with the black stripe prominently marking the lower lobe.

Pectoral fin

Small, clear pectoral fins.

Distinctive fins

Presence of a small adipose fin between the dorsal and caudal fins.

Identification Tips

1. 1

   Black Lateral Stripe

   The most defining feature is the distinct black stripe that runs horizontally along the body and angles downwards into the lower lobe of the caudal fin. This is a key differentiator from other similar tetras.

2. 2

   Swimming Posture

   Thayeria boehlkei often swims with its head slightly angled upwards, giving it a unique 'penguin-like' appearance. This behavior is quite characteristic.

3. 3

   Body Shape and Size

   They have a slender, torpedo-shaped body, typically reaching a maximum size of about 6-7 cm (2.5-2.8 inches) in length.

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