It is a physiological fact that any organism with a complete digestive system needs an organ such as the ‘Tongue’, which some may pronounce as ‘Tounge.’
But it doesn’t matter as long as it is the same organ that we wish to learn about in fish.
Fishes have a well-developed digestive system to aid their food intake from a variety of sources-plants, animals, minerals, etc. But do fish have tongue to taste that food.
Imagine a scenario where you and I have no tongue!
I’ll bet that it would be a depressing moment to think about the flavors of our favorite ice cream or even to come across the phrase, ‘Finger Lickin’Good’ of Kentucky Fried Chicken.
Keeping all these thoughts of ‘delicacies’ aside, let’s learn something about Fishes concerning their Tongues.
So, Do Fish Have Tongues?
Before affirming this inquiry, it is crucial to understand the basis behind describing the organ as ‘tongue’ is mainly attributed to its functionality.
So, we cannot anticipate a fish’s tongue to be exactly like ours in terms of anatomy and structure, but Yes, Fish do have tongues.
Comparison of Fish (Marine) and Human (Mammal) Tongue
- Location– It is located at the start of the digestive system, i.e., Mouth Cavity/ Buccal Cavity.
- Function– They aid in the movement of food components towards the stomach in addition to tasting food.
- Retractability– The tongue can elongate and withdraw with stimuli and nervous control.
- Structure– Mammals have a muscular tongue, whereas fishes have bony/ cartilaginous tongues.
- Taste Buds– They are highly specialized and abundant in mammals, in the form of papillae. In contrast, they are limited in most fishes.
- Relation with Hyoid Bone– In mammals, the hyoid bone and tongue are two separate components. The tongue of fish is commonly called Basihyal, a modified form of the hyoid bone.
Fish Tongue Morphology and Anatomy
Generally, fishes do have tongue and it is a roughly triangular-shaped apparatus comprising an Apex, Body, and Base.
The inner portion comprises hyaline cartilage/ bone, and a layer of mucosa and submucosa covers the surface. The thickness increases towards the base.
Specialized Function of Tongue in Fishes
As we know, taste buds are scarce in the tongue of fish, and doubt may emerge as to ‘why do fish have tongues?’ if it is not a major organ for tasting like us.
We may satisfy our thirst to know the ‘why’ by realizing that the tongue of fish has multiple functions in addition to the ones mentioned earlier.
- Processing Prey– This function is a unique modification found in the Super-Family of the genus Osteoglossomorph. The tongue of these fishes has a special characteristic in the form of tongue-bite apparatus (TBA) to shred and disable prey.
- Sucking– The tongue/ basihyal is an essential organ in fish for taking in water from the surroundings. This is possible by creating space for water inside the buccal cavity for water to flow in and vice versa.
- Protective Function– Researchers generally believe that the basihyal is modified to protect the ventral aorta from external threats.
Do Fish Tongues Have Teeth?
No, they do not have it. The adaptive features present in certain species of larger bony fish (Osteoglossomorpha), having ‘teeth on the tongue’ (mentioned earlier), is a misconception.
Here the tongue is specialized to act as an opposing surface for the teeth present in the jaw while chewing.
Can Fish Tongues Have Taste Buds?
A recent study has shown that the fish tongue contains taste receptors in the form of mucous cells.
Although the receptors are not well developed as mammals, they have their role to perform in determining the food habits within the niche of their environment.
Species variation also determines the intensity of taste receptors among different fishes.
It is understood that benthic/ deep-water fish living in biologically rich habitats have more taste receptors compared to other environments.
Likewise, freshwater fish has a higher number of taste receptors.
Do Goldfish and Betta Fish Have Tongues?
Yes, they have tongues. Moreover, they are classified under the freshwater inhabitants with numerous eating habits.
It is practically possible that they have more taste receptors in their tongues.
Anomalies in Fish Tongues
There are certain circumstances in that aquarists may encounter a ‘fish with its tongue out of the mouth’ or supposedly a prominently overgrown tongue.
These sights are not pleasant to glance at as they can be due to a pathological or parasitic infestation. Let’s understand further specifically.
- Tongue Tumor/ Odontoma– Despite its prevalence being rare in most fishes, it has relevance to its contribution into the excess growth of the basihyal/fish tongue. It can also be misdiagnosed with parasitic infestations, which we will look.
- Fish Tongue Parasite– This condition is caused by multiple species of parasites from the Genus Cymothoa spp.
The prevalence of this infection can be as high as 45% or more in smaller fishes.
The Isopod/Cymothoa organism finds its way to the base of the tongue through the gills.
Blood supply may be completely disrupted resulting in the withering of the tongue, after which the female Isopod replaces the tongue and acts as an artificial replacement for the fish.
How creepy, don’t you think?
Harmful Effects of Tongue Anomalies in Fish
Although the infected fish may survive it, everything cannot be the same as before. They may face negative consequences in the following ways:-
- The volume of the buccal cavity will reduce considerably, impacting the food intake capacity.
- Oxygen deficiency leads to respiratory distress due to buccal obstruction.
- Stunted growth as the nutrients are shared with the parasites.
Curiosity to find out if fish has a tongue is irresistible. More research needs to be done to unearth more information on this useful organ in fish.
The tongue has a complex role to play in the overall survivability and growth of the species.
It never fails to amaze us to understand how a bony composition of the fish tongue is more than just cartilage!