NOUN
- unpaired median fin on the backs of fishes and some other aquatic vertebrates that help to maintain balance
How To Use dorsal fin In A Sentence
- The fins have strong leading rays, which form a row of sharp spines along the dorsal fin.
- As the water tumbles over the huge boulders forming a great cloak of foam, the dorsal fins of the salmon along their blue/black backs pierce the sudsy water like an emerging submarine.
- Hippocampus severnsi is distinguished from congeners in having a combination of: extremely small size (height 13 mm, standard length 15 mm); 12 trunk rings; 27 tail rings; reduced ossification of inferior and ventral trunk ridges; 14 dorsal fin rays; 10 pectoral fin rays; anal fin small or absent; medium length snout which lacks a bulbous tip; raised, angular coronet; single gill opening on midline directly behind coronet supported by raised cleithral bone; scattered tubercles on trunk and tail; predominant colour dark brown (sometimes slightly marbled) with large, bright red patch covering dorsolateral surfaces of trunk rings 1-4; tiny white dots scattered all over; pale posterior section of tail with dark transverse bands. Practical Fishkeeping news (RSS)
- The ocelli (eye-like spots) on the spinous dorsal fin of males are metallic blue, surrounded by a golden ring.
- The shape of the elongated spiky dorsal fin is reflected in the sweep of the flowing ventral fins.
- The dorsal fin generally was uncoloured, unspotted, and semitransparent.
- Some snipefish, such as the ones on the cover, also have a long, pointed spine stretching back from the dorsal fin.
- The cutlassfishes are characterized by a scaleless, band-shaped body tapering to a slim pointed tail, with one dorsal fin extending the whole length of the body; the anal is also long but is very low.
- An anglerfish depends on its prey being fooled by its camouflage and by the fleshy lure into which the first ray of its dorsal fin has been modified.
- Reproductively active individuals may have a uniform dark gray body with pale abdominal striping and a pale margin on the spinous region of the dorsal fin.