The American paddlefish, polychaete, or paddlefish (Polyodon spathula) is a species of freshwater sturgeon in the paddlefish family. It is found in the Mississippi River basin and Lake Huron. 1)
The Picasso triggerfish (Rhinecanthus aculeatus) is a species of marine blowfish. It inhabits coral reefs and is kept in aquariums. 2)
The snout — a rostrum shaped like a horizontally arranged paddle — is sometimes half the length of its entire body and functions as a sensory organ. 3)
The toothless Garra rufa can feed on the exfoliating epidermis of people suffering from certain skin conditions such as psoriasis. 4)
It characteristically grabs its food, which consists mainly of pelagic crustaceans, swimming with its mouth wide open in a zone devoid of vegetation, filtering out planktonic organisms with long and dense filtering appendages (juveniles initially have teeth that become resorbed over time), staggering in circles and often in eights. 5)
The candiru (Vandellia cirrhosa) lives in the rivers of the Amazon and feeds exclusively on the blood of larger fish, entering their gills and biting through their blood vessels. It satisfies its hunger within a minute and swims away in search of new prey, which it finds by the smell of ammonia emitted from its prey's gills as it breathes. 6)
The body of the fish has a multicolored arrangement of streaks and spots reminiscent of Pablo Picasso's sketches, hence the usual species epithet. 7)
It spawns in early spring in rivers and lakes in turbid water with sandy gravel or rocky bottom. The female lays 80-250 thousand grains of eggs. She then forms large flocks that swim into larger tributaries or lakes. In its habitat, it stays away from the shore at considerable depths. 8)
Treatment involves submerging the limbs, sometimes even the entire body, in an aquarium with these fish. One treatment usually takes up to 30 minutes and several hundred fish are needed. Opponents of ichthyotherapy draw attention to the risk of waterborne diseases. 9)
Picasso's Triggerfish has been used in studies of color vision in fish. 10)
In natural conditions, they feed on algae and small organisms living there. In the aquarium, they should be fed with plant food such as spirulina tablets, cucumber, melon, spinach, or zucchini supplemented with frozen and live animal food such as chironomid, tubeworm, or artemia (chopped earthworm). 11)
There are cases when candiru enters the urinary tract of large mammals, including humans who urinate in the water. Heading upstream of the flowing urine, the fish enters the urethra and falls into a trap from which it is impossible to escape because of the sharp spines. The fish dies but can only be removed surgically. 12)
The coastal dugong (Dugong dugon) is a marine mammal belonging to the order Coastals. The eyelids of dugongs contain glands that secrete an oily fluid that protects their eyes from being damaged by the salty seawater. After pulling the dugong above the water's surface, this secretion collects in the corner of the eye and forms what is commonly called a “mermaid's tear”. These are used by some peoples of Oceania as an amulet. 13)
For too long “peeping” Picasso can “chase” the diver, nibbling or biting him with quite big teeth (8 at the top and bottom). This attack is not dangerous but can be a real surprise for the unsuspecting diver. 14)
Commonly known as “sea cows”, dugongs graze peacefully on seagrasses in the shallow coastal waters of the Indian Ocean and western Pacific. 15)
Note that these fish can move vertically or hover like a helicopter. 16)
Dugongs are cousins to manatees and have a similar plump appearance, but have a tail similar to dolphins'. 17)
Because paddlefish is considered to be an ancient species, it is illegal to harvest for caviar. Harvesting paddlefish is considered poaching. 18)