Madeira Canary Islands Azores – Fishes Dr. Peter Wirtz

The first dorsal fin of rocklings is modified into a sensory organ. The fin rays are very short and lie in a
groove. The fin permanently performs a rapid, undulatory movement that draws water through the groove.
Sensory cells then test the odorous substances in the water. During the day, rocklings hide in caves or below
boulders. The Spotted rockling mainly feeds on crustaceans. Reproductive season is in early summer. Photo
Peter Wirtz.
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Needle fishes (Belonidae)
Garfish (Belone belone)
Up to 90 cm long. Madeira, Canary Islands. 0 – 10 m depth.
Needle fishes usually swim directly below the surface of the water, in small groups or alone. Both jaws are
greatly elongated. Needle fish capture their prey, mainly small fish, with a lightning-fast sidewards movement
of the jaws. Reproductive season in the summer. The eggs are glued to plants by small, sticky threads. Photo
Peter Wirtz.
Sand smelts (Atherinidae)
Sand smelt (Atherina sp.)
Up to 10 cm long. Madeira, Canary Islands, Azores. 1 – 30 m depth.
The different Sand smelt species in the area (Atherina hepsetus, Atherina presbyter, possibly also Atherina
boyeri) cannot be told apart on first glance. Sand smelt are frequently confused with sardines. But they do not
have a silvery body, only a silvery line along the body. Also they have two small dorsal fins, not only one.
Sand smelt often form very large schools in shallow water. They are important food for many predatory fish