Batrachoidae or Frogfishes.

Some time ago at one of my visits to my friend Ton Cooijmans, of Tropifish at Beek en Donk he drew my attention to a number of very strange fishes, in one of the stock tanks. The fishes looked some how like frogs or better like tadpoles. The best resemblance has the big flat goggle-eyed head and the naked skin. The mouth rather wide is armed with sharp little teeth that look alike the incisive teeth of a mammal that leads to one suspect that these fishes are greedy carnivores. They also had the proportions of a strapping tadpole. But some time afterwards I came across a specimen of at least l 13 CMS.

Batrachoides didactylus, Daector quadrizonatus.of Thalassophryne zonatus ?
Probably they got their name from this tadpole-like form. (Batrachos is frog). The family of the Batrachoididae is the only family out of the order of the Batrachoidiformes. The little first dorsale is composed of two or three shafts. The second dorsal fin is very flexible and very long and looks alike the arsfin The pectoral fins are well developed and the the pelvic fins that are on the throat. The Batrachoides didactylus, that especially occurs in the eastern part of the Atlantic Ocean is a rather ugly fish with a enormous flat head and little eyes. The muzzle is big and the teeth consist off sharp little teeth. He also has different appendages of the skin, specially around the mouth. The color of the back of the fish is yellow-like with brown stripes and the belly is grayish. In spite of the fact that this fish is innocent it is handled with care by the fishermen because of its terrifying appearance. Much more dangerous is the specimen
Batrachoides didactylus, that lives near the coasts of mid and South-America. These fishes posses an effective weapon.
The dorsal fin has namely two hollow spines that look like the teeth of poisonous snakes. At the base of these spines is the poison gland. A bite of this fish is very gainful: the pain can insist during hours and the heartbeat and the breathing go slower. With the passage of time these symptoms disappear. If the wound isn't nursed well it will fester seriously. Established is that several specimen of the genus Thallasophryne regular intervals move from deep water to very shallow water. That migration appears to be connected to the reproduction of these fishes After some time they return again to deep water They are able to stay alive outside of the water. They can during some hours in succession stay on dry land, without they re the worse of it. In water that containing very little of oxygen, They can normally stay alive .
Several species produce noise when they are taken out of the water. They utter tan dull sounding noises, that generally sound like a kind of whirring or a hoarse growling and in some cases like someone in the distance is blowing a foghorn. This sound is
so clearly audible, because of the swimming bladder is serving like a kind of resonance box.
Ruud Wildekamp says that in South America, where the specimen in our pictures come from, the next species are found:
Daector quadrizonatus.
Thalassophryne zonatus
in Peru, and
Thalassophryne dowi
the last one by a Mr. Wilson in the Rio Truando in Colombia in the Truando basin.

Grzimek Het leven der dieren Utrecht,Antwerpen 1974. Blz. 458 e.v. Gunther Sterba Enzyklopädie der Aquaristik und speziellen ichthyologie Leipzig 1977 Nieuwenhuizen, A van den, Zoetwaterimporten Het Aquarium 1975 1976 Sterba, Gunther Enzyklopädie der Aquaristik und speziellen ichthyologie Leipzig 1977 Lekturama Wonderen onder de Waterspiegeldl.8 vissen Rotterdam