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The types of freshwater eels are known to be the important fish species, they are known to be as food in Belgium, France, Great Britain, as well as The Netherlands. The eels are one of the most known fish group that would sit with the seahorses and sharks as types of fish that you can easily recognize. But, this is not really true. In this article, we will know more about the type of freshwater eel instead of having a long, snake-like body, and just as it can’t get any clearer, every freshwater fish has this common name. With this, they are not really the type of freshwater eel.
In the field where the true type of freshwater eels might have failed, other groups have managed to successfully adapt to their morphology to their matching. These are also worked so well for the true anguilliforms. The following are the impostors of the eel family.
This might be the kind of eel that is most likely to be confused by the aquarist with a true eel. However, their name gives them as being an anguiliform in shape. No spines in their fins could ever be seen in the true eels. Their spiny cousin found in the Mastacembelidae coud have around nine to 42 spines found on their dorsal fin while two to three in their anal fin. These fin found on their spines would help us to know that these types of freshwater eels are from a huge group which we call the Acanthomorpha. They are also close family members to the perch-like fishes.
Another unique quality of the mastacembelid eels is the presence of their specialized pouches found above their gills. They function like a lung, similar in many ways to the suprabranchial organs which we can find in the gouramis. We know that they are closely related and they have common ancestors that have emerged somewhere from the Southeast Asia or Africa. They existed during the time when the dinosaurs were wiped from existence from 65 million years ago. This is the important freshwater lineage which we can still find in the Old World, with a great exception of a few Central American Swamp Eels.
Around 90 species we know come from the spiny eel family, however, one of these is placed in the highly similar genera. These are the Macrognathus and Mastecembelus. These two species could range from a tiny size, 3-inch African species which we can find in the rapids of the Congo river up to the monsters like the Fire Eel. The latter is the known largest of all spiny type of freshwater eels, which could reach over a meter in length.
They are also a common specie in the aquarium trade,their smaller relatives are very important to researches. You also need to research about these fish before you add one to your tank. If you have an adult Fire Eel, it could eat up your smaller fish, though, generally, they are really peaceful to anything that is too large for them to swallow. Luckily, they can also be kept in large groups together, but they could quarrel among themselves if you keep them in small numbers.
The unusual reedfish belongs to the not so type of freshwater eels. It has an interesting history and would sit in a good spot of the bony fishes. The closest relative of this eel is the bichirs, they represent the oldest surviving lineage among all the bony fishes, the order Polypteriformes, it has a record that extends back up to the Devonian sometime 400 million years ago. This is evidently seen in their primitive morphology of their skull, the peculiar finlets found along their backs, and the chunky structure of their pectoral fins. We can say that they are really hardy creatures because they are the true survivors.
This fish is the only existing member of the genius so essentially a type of freshwater eel version of the more burly bichirs. They are typically seen in the swamps of West Africa, they emerge at night and the invertebrates. When they live in the aquarium, they are relatively peaceful and timid. It is best that you keep them away from other overly boisterous animals. They have a diet of meaty food, which they can be served as frozen or fresh. However, take good care for smaller fish could also be in the menu. They are typically one foot in length and could be housed in a fairly small aquarium. You need to have all the openings tightly covered. Remember, these eel like fishes are escape artists, and nothing is more saddening as seeing a dried up eel on the floor.
Dojo & Kuhli Loaches
The loaches is another group of eels. They have taken an anguilliform lifestyle. Most of these types of freshwater eels that we know as the loaches are not really eel-like in their shapes. This is not really drastic in fishes such as the Skunk Loach or the Clown Loach. They have a tendency to become morphologically atenuated and would start to predominate other members of the loach family. Many of these are really rare inside the aquarium, but we need to mention the Kuhli Loach and the Dojo Loach.
The two mentioned loaches belong to the true loach family which we call the Cobitidae. They are pretty common for this group They have extremely elongated bodies and their fins are reduced in size. They typically move by wiggling their bodies against the substrate. The Kuhli Loach is the more popular oddball for the peaceful community in your aquarium while the Dojo or Weather Loach could be used as a bottom-feeder. Both of them do great with a diet of meaty food and you must keep them from jumping out of their aquarium or into the filtration equipment inside.
Prehistoric Dragon Goby
Similar to what we have just described, these gobies are a group of elongated fishes and a great example of type of freshwater eels that may sometime take things to an extreme level, the great example of which is the bizzare Gobiodies. It is a small Atlantic genus that can be found in the coastal habitat, it could be brackish or freshwater. In here, they ingest nutrient rich muddy bottom for whatever edible morsels they can see. Although it might not really sound a healthy diet, the specimen of the common G.broussonnetti, have been recorded at almost 2 feet in length! The common size for this fish is around 10 inches.
The Gobioides have a lot common names, the name include the Violet Goby, descriptive Eelgoby, and another whimsical aquarium name Prehistoric Dragon Goby. The Gobioides is a great addition for aquarists, however, it would require great forethought and planning, because the goby tends to not compete with other type of freshwater eel species especially when it comes to feeding, so you need to consider other specialized husbandry requirements.