Pelagic fish (1)

As a whale-watching company, our primary goal during our tours is to enjoy sightings with the cetaceans roaming around the waters of the Madeiran archipelago but the deep blue waters of the Atlantic also contain other hidden treasures, many of which can also be encountered at the surface.

Part one: The shelter seekers

If you’re a small to medium-sized fish, the open ocean can be a formidable place, a blue desert. Often it is difficult to find a decent meal or find shelter from lurking predators so we often encounter many of the listed species under both living and non-living floating matter during our trips. Anthropogenic debris is often an opportunity for food and shelter. Planktonic larvae hinge onto non-living objects and develop into invertebrate adults, such as barnacles and oceanic crabs, providing an easy, convenient meal for different foraging fish species. Epifauna on basking Loggerhead turtles (Caretta caretta) are also a great source of food while the Potuguese-Man-O-War (Physalis physalis) can act as an effective guardian against predators.

Since we encounter floating objects and animas fairly often during our trips, particularly on our zodiac Stenella, we also have some footage and photos of the animals.

Snipefish (Macroramphosus scolopax)

The snipefish saw a high abundance this year and now probably belongs to the unluckiest fish you are likely to encounter in Madeira. These googly-eyed, terrified-looking little guys occur in oval-shaped schools that are relentlessly pursued by a variety of predators including tuna, marlin, baleen whales and several species of dolphin. They are also prone to airborne attacks by shearwaters and other marine birds. The streamlined body of this little fish contains a long dorsal spine and a long snout with a tiny terminal mouth which it uses to feed on plankton. The species mainly occurs in subtropical and tropical regions and can be found up to depths of 600m. We often see schools of these fish desperately trying to escape from the dolphins and birds pursuing them and, as they flee, the fish often swim underneath our boats in an attempt to hide from their hunters. While this doesn’t help the fish escape, they certainly help us achieve a closer encounter with marine mammals.

Grey triggerfish (Balistes capriscus)

If you see a large piece of floating debris at the surface, such as a box or a bucket, keep a sharp lookout for these guys. Triggerfish earned their name from the second spine on their dorsal fin, that triggers the erection of the first when pressed downward. This along with the animals undulating posterior dorsal and anal fins allow it to effectively wedge itself inside corners or crevices when the animal seeks shelter. Although it occurs at the surface, this fish is actually a demersal feeder that uses the large powerful teeth inside its fleshy mouth to crack open shells of benthic crustaceans, echinoderms and molluscs. Apart from occurring in certain parts of the Eastern and Western Atlantic, the Grey Triggerfish also inhabits the Mediterranean sea.

Atlantic Tripletail (Lobotes surinamensis)

If we’re lucky, we may also encounter an Atlantic tripletail near anthropogenic debris at the surface, the only species of the family Lobotidaethat occurs in the Atlantic ocean. This largely solitary pelagic fish can reach lengths of up to 90cm and often floats on its side when swimming at the surface, making it look like a floating dead leaf.

Pilotfish (Naucrates ductor)

We generally encounter adult Pilotfish near basking marine turtles while juveniles often congregate under cnidarians such as the Portuguese-Man-O-War. Their diet consists of ectoparasites which are carefully nibbled off, making them somewhat of a cleaning station for the turtles, sharks and rays that also serve as their shelter. Their common name, Pilot fish, is hypothesised to have many sources. Seafarers believed that Pilotfish aggregations at their ships bow was a sign that they were close to port and that the fish were practically leading them there. Other etymologies for the term make reference to the fact that the fish accompany many animals, particularly sharks, for a substantial amount of time.

By Paula Thake