While discussing the guideline on what should be the diet of a tarantula with my friend, he showed me an interesting video link – tarantula eating a fruit. While tarantulas are largely a carnivore, can they eat fruits? Should we add it to their diet?
Let’s put out the answer straightforwardly – no. ‘Eating’ something is different than ‘Digesting’ it. While they can ‘eat’ it, they do not necessarily have the right digestive enzymes for it. Some might eat bits and pieces of fruit and not have a problem while others might get digestive issues. Tarantula’s ideal diet should undisputedly be a carnivore one.
We judge the nutritional value of food on the digestive capability we have and what we can derive from it. So how do we decide it for our very own tarantula? Read on to understand what goes inside the digestive process of your tarantula.
A Tarantula’s Digestive Process
The Vampire Tactic
Your tarantula doesn’t eat and digest food the way we do. They have fangs that help them puncture wounds into their prey’s body (even their hard exoskeleton) and inject venom.
They then wait for the venom to take action and put the prey to sleep. But what is more interesting to find is that along with the venom, they also inject digestive fluids into the prey’s body.
Tarantulas can eat and digest their prey if they have been liquefied enough for them to gobble up. It doesn’t have to be a liquid mess or runny. The consistency of a thick smoothie or even a paste would do them good.
Judging from the types of prey they eat, they are mostly hard-shelled and have exoskeletons. Hence, they also coat their prey with additional digestive fluid orally to fasten up the process.
This is where the mixture of venom and digestive juices comes in handy. Venom relaxes the muscles of the prey while digestive juices slowly make it eatable for our hungry tarantula. They really have to wait for a while to enjoy the whole meal.
Vacuuming The Nutrition In
We humans chew food and voluntarily push it down our throat via our tongue. But tarantulas don’t have the same mechanism. They have a ‘sucking stomach’. Their entire stomach acts like a pump, which suctions the food particle inside their stomach.
Once it reaches their stomach, it is again washed down by other digestive enzymes. Their stomach also has a number of sacs/pockets called caeca.
These pockets will store away food particles, which the tarantula cannot digest right away or wants to digest later on when it feels low on fuel. This is why they can persist without food for as long as a year – especially when they had larger prey.
When they are done eating their food, their intestine will break the food further down to get as many nutrients as they can. After that, the remains will be expelled out in the form of a ball.
Taking A Closer Look At The Digestive Fluids
Spiders, in general, have the same kind of eating mechanism. Tarantulas also share the same functions, except that it doesn’t wrap its prey in a silk web to trap them.
They directly attack them and inject their venom via their fangs. But what does their digestive fluid have? It is necessary to know what digestive enzymes we are working with so that we get the most out of the food we eat.
You can eat your pizza along with the cardboard box that comes with it. But would it be digested well by your stomach? No, because our digestive system cannot breakdown cellulose.
The same goes for tarantulas – just because they can eat something, doesn’t mean they should.
Complexities In A Tarantula’s Digestive Function
It wasn’t known earlier that spiders inject digestive fluid along with the venom to liquefy their prey.
After years of specific research on a few species of spiders, it was found that they do inject digestive fluid. However, we don’t know in what ratio do they mix it up and inject in their prey.
Spiders have at least 300 to 500 enzymes that help them in digesting their food. A combination of these enzymes gets active at different levels of the digestion process.
The main function of these enzymes is to convert food particles into proteins that will be distributed in their bodies.
Spider’s main prey is mostly insects. They are rich in proteins and lipids. It is easier for spiders to coat insects with their digestive fluid and liquefy them compared to other larger prey such as rodents.
This action also helps them to fight off pathogens and bacteria that may be present in the body of prey. In a way, it helps them to ‘sanitize’ the prey before eating.
While they can eat almost everything that they can liquefy, we need to know what it does after liquefaction.
Absence Of Hyaluronic Acid In A Spider’s Digestive System
In most of the spider species, hyaluronic acid enzymes were absent in their digestive fluid. Since their main prey (insects) do not have hyaluronic acid in their bodies, it was understandable that it might not be present in them as well.
However, there were one spider species that used some amount of hyaluronic acid – present in their venom as well as their digestive fluid. This acid helps in breaking down extra-cellular molecules in food, which is generally termed as ‘non-prey’.
If a general spider is eating a non-prey food, they might need hyaluronic acid to actively break down extra-cellular parts of the food.
While the ‘prey’ will be somehow broken down into liquid mess, since the spider doesn’t have the enzyme to properly digest anything rich in hyaluronic acid, it would create digestion problems in a spider.
This goes for tarantulas too. Either the tissues having hyaluronic acid will be avoided by the spider or would be expelled out of the spider’s system.
The Mystery Of ‘Fruit-Eating’ Tarantulas
This topic has been discussed in the tarantula owner community where they have either accidentally discovered their tarantula eating bits of fruit or they would sneakily add some bits of fruit in their dead prey.
They seemingly don’t look like they have any digestive problem. But is it healthy?
Also, since tarantulas are fussy eaters and can also store food in their sacs and pockets, we wouldn’t know which food will adversely react to their digestive system and when.
As they are neither vocal nor expressive when it comes to showing any pain or discomfort, it is best to stick to their regular carnivore diet.
The best bet we have is that they suck out the juices in the fruit. In such cases, citrus fruits might not do good to them, as it is rich in hyaluronic acid. Also, they might not have enough enzymes to get any nutritional value from fruits.
How do enzymes in fruits interact with venom and digestive fluid – especially when a tarantula’s approach to eating food is directly attacking it with fangs and injecting a cocktail of fluids?
This would make up for a good research subject in the future. But for now, we are only left with more complicated questions than answers to it.