Come identificare Brook Lamprey

Per identificare Brook Lamprey (Lampetra planeri), osserva queste caratteristiche chiave.

Caratteristiche fisiche

Forma del corpo

eel-like

Colorazione

Adults are typically dark grey to olive-brown dorsally, fading to a lighter, silvery-grey or yellowish-white ventrally. Ammocoetes are uniformly yellowish-brown or greyish-brown.

Tipo di squame

none

Posizione della bocca

inferior

Caratteristiche distintive

Absence of jaws, paired fins, and scales., Seven gill openings (pore-like) on each side of the head., A single nostril on top of the head., Oral disc with blunt, unicuspid teeth arranged in specific patterns (diagnostic for species)., Two dorsal fins, often contiguous or very close together, with the second dorsal fin continuous with the caudal fin.

Pinna dorsale

Two dorsal fins, the first smaller and triangular, the second larger and continuous with the caudal fin. The two fins are often separated by a small notch or are barely contiguous.

Pinna caudale

Caudal fin is rounded or spatulate, continuous with the second dorsal and anal fins, forming a continuous fin fold around the posterior end.

Pinna pettorale

Absent

Pinne distintive

Absence of paired fins (pectoral and pelvic fins).

Consigli per l'identificazione

1. 1

   Size

   Adults typically range from 10-16 cm (4-6 inches) in length, rarely exceeding 20 cm. Ammocoetes can reach similar lengths before metamorphosis.

2. 2

   Oral Disc

   The oral disc of Lampetra planeri is relatively small and lacks the strong, sharp teeth found in parasitic lampreys. The teeth are blunt and unicuspid. The arrangement of teeth (e.g., number of anterior labial teeth, presence/absence of supraoral lamina) is crucial for species identification.

3. 3

   Dorsal Fins

   The two dorsal fins are typically separated by a very small gap or are barely contiguous. This distinguishes it from some other lamprey species where the fins are widely separated or completely fused.

4. 4

   Non-parasitic Nature

   Adults do not feed. Their gut is atrophied, and they lack the strong, rasping teeth of parasitic species. This is a key ecological distinction, though not always observable in the field without dissection.

5. 5

   Coloration

   The generally drab, olive-brown to grey coloration with a lighter underside is characteristic.

Esplora Brook Lamprey