The whale fish (not to be confused with the whale shark) is a relatively newly discovered species of fish (not whale), so information regard this species is somewhat limited.
The whale fish gets its name from the fact that its visual appearance resembles that of a whale, however they are much much smaller than a whale and because they are fish they are physiologically different as well.
For instance fish are generally cold-blooded, breathe through gills and lay eggs while whales are warm-blooded, breathe air through their blowholes and give birth to live young.
In terms of size an adult male whale fish can grow to lengths of up to 3.5 cm while female whale fish may grow up to 10 times the size of their male counterparts measuring in at up to 1.3 ft in length.
As stated earlier most people will easily notice these fish aren’t nearly as large as even the smallest whale species.
For example the smallest whale is the dwarf sperm whale which reaches lengths of around 9 ft. long while the largest whale is the blue whale which can grow to lengths in excess of 100 ft.
It would likely take 9 female whale fish to measure the length of even the smallest whale species.
When it comes to diet these fish tend to have a unique way of obtaining nutrients.
Interestingly the male whale fish is unable to open its mouth preventing it from consuming food during its adult phase.
In order to continually be provided with nutrients and a food source male whale fish retain the shells of prey they have captured during their juvenile phase and will continue to use those shells as a source of food and nutrients throughout their life.
Female whale fish on the other hand are able to consume prey and have an expandable stomach which allows them to consume and digest large prey that would normally be too large to consume and will hold their prey in their stomach until the food is able to digest itself over time.
During the night (when predators are less likely to strike) whale fish can be seen migrating upwards to find and consume their prey.
During the daylight whale fish will migrate back down to avoid possible attacks from predators.
It is believed that the female whale fishes diet consists of eating crustaceans.
Whale fish are among some of the deepest known species of fish swimming at depths of up to 12,000 ft. where the ocean is completely pitch black.
To assist with navigating the dark ocean female whale fish have developed an advanced sensory system which allows them to detect slight vibrations in the ocean so that they can detect objects in the surrounding environment and avoid potential attacks from predators.
As far as reproduction is concerned little is known about how the whale fish species reproduces its offspring.
What is known is that one of the few primary roles of an adult male whale fish is to provide the female with sperm so that it can produce offspring.
Other than that males whale fish appear to play a relatively small role (if any) in regards to raising or caring for their offspring.
Helpful Resources
- Wikipedia: Flabby whalefish
- Wikipedia: Velvet whalefish