Seahorses are a fine example of nature’s exuberance of evolution, these tiny creatures resembling the Knight in a chess game are most commonly found living in coastal sea waters. The exquisite grace and perfection with which they float among the coral reefs & seagrass beds on the hunt for plankton and small fishes is truly a sight to behold.
So, do sea horses bite? Seahorses do not have teeth and hence they cannot bite. A lot of research has happened to determine how exactly did the sea horses lost the genes to develop teeth. Recently a team of marine scientists had a breakthrough and found out that down the evolutionary lane, sea horses lost the genes for enamel proteins causing the loss of mineralized teeth.
Sea Horses – A lethal hunter without teeth
The way magnificent creatures appear to float around peacefully through the coral reefs or grass beds is truly a sight to behold. Though they are not generally aggressive they are no less than a lethal hunter.
Sea horses are truly an enigma of the marine ecosystem. Though they are fishes their digestive system, the way they consume food, their hunting techniques they all drastically differ from their close relatives.
A predator without teeth?
The genes responsible for developing mineralized teeth and enamel are not found in sea horses. Down the evolutionary lane, they developed long tubular snouts with a small mouth and no teeth.
Unlike the other fishes that use their mouth to catch prey, sea horses use their long snout to suck in their prey like a vacuum cleaner.
These teeny weeny creatures with a small mouth and a long snout mainly eat planktons, small fishes, copepods, brine shrimps, mollies, side swimmers, guppy & rotifers. Basically, anything that crawls at the bottom of the ocean or floats in the water is potential prey for them.
Let us have a close look at the way the hunt & digest their prey.
Sea Horses – The camouflaged hunter
Sea Horses are one among the marine life forms with the ability to change its color and they do it for all sorts of reasons. They may change color to mimic other organisms, to blend in with their surroundings, to deter predators or to pound upon their prey stealthily.
Sea horses have sack-like organs called chromatophores embedded beneath their skin. Each sack contains 1-4 pigments which are controlled by the contraction and relaxation of the tiny muscles controlling the chromatophores. The intensity of contraction or relaxation results in the different colors being displayed in varying intensity.
The chromatophores are controlled in 2 ways:
- When rapid camouflage is needed – Controlled by Nervous System
- During breeding & courtship – Controlled by hormones
How do sea horses hunt?
Sea horses are not good swimmers neither are they swift but they know to make the best out of their stealth. It is for this reason they are most commonly found anchored to corals or seaweeds using their prehensile tails.
When a Sea Horse spot a prey they move slowly and silently towards the prey without alerting them. Once the prey gets into their kill zone they rotate their neck and bring the long snout close to the prey and slurps them in.
Sea Horses have three feeding phases
Preparatory: This phase involves stealthily approaching the prey without alerting it. Once the prey is in the kill zone the neck is flexed ventrally and the long snout is brought close to the prey.
Expansive: In the expansive phase buccal cavity is expanded, head in the lifted position, and the prey is sucked into their mouth.
Recovery: Once they have swallowed the food the hyoid apparatus, head & jaw are brought to their original position.
Sea Horses are not always into aggressive hunting. It is seen that the presence of vegetation around them greatly influences their eating behavior.
When in areas with a small vegetative cover they prefer to stay anchored to corals or seaweeds and wait patiently for the prey to walk into their kill zone. In places, with extensive vegetation, they keep an eye open for prey they are even found feeding while swimming through these regions.
How often do Sea Horses eat?
Another puzzling fact about sea horses is the absence of a stomach. Whatever food they eat it goes straight to the digestive system and the nutrients are absorbed fast. In order to survive, they have to eat constantly.
“A young sea horse can eat approximately 3000 pieces of food a day while a fully grown sea horse eats 50 times a day”
The digestive system of a Sea Horse
The digestive system of a sea horse is fairly simple. They don’t have a mouth, teeth or stomach, unlike other fishes. Which means the food is not broken down until it reaches its intestine. It is for this reason sea horses have to eat constantly for survival.
The process of digestion in a Sea Horse (Happens in the digestive tract)
- Food is swallowed by the sea horse.
- The swallowed food goes down a tubular structure named the esophagus and reaches a sack-like structure (A minimized stomach). The liver produces bile that helps breakdown the food particles.
- The food then moves to an intestine where nutrients are rapidly absorbed.
The process of excretion in a sea horse
The excretory system of a sea horse consists of a kidney, urinary bladder, and an anal fin. The waste in the blood are filtered out in the Kidney and is directed to the urinary bladder and in released out from the body as urine.
The solid wastes from the small intestine are sent to the anal fin and are excreted.
“Did you know that sea horses do a special 360-degree movement to excrete the waste from their body?”
Can I feed a Sea Horse in captivity?
It is possible to keep a sea horse in captivity but it is not for inexperienced keepers. Sea Horses are not used to eating frozen food or fish food rather they only eat prey that is alive. If you are so keen on having them in an aquarium
- Feed them in frequent intervals of time
- Mix frozen food with prey that is alive. This will help them slowly adapt to the new environment
- Maintain proper salinity and oxygen saturation of the aquarium water.
- Place seagrass and grow small water plants to make your sea horse feel home.
Additional give away!
- Did you know that male sea horses give birth to babies?
- Sea Horses are found to make synchronous movements with their mate resembling graceful dance movements
- During breeding and courtship, the hormonal changes in them cause rapid color changes.
- Sea Horse population has drastically dropped in the past years owing to pollution, extensive fishing, climatic change, and a lot more reasons.