Adult whale sharks may be the largest living species of fish in the world but their darling little neonates are far off the mark when it comes to claiming this impressive title.
In this article, we explore everything there is to know about the baby whale shark from birth, growth, feeding all the way to maturity and adulthood. Stay put and don’t go anywhere.
The baby whale shark
Neonate whale sharks also known as pups are born at an average length of 55 cm and weigh only a several few pounds when measured against a beam scale.
Their typical birth length falls between 40-70 cm (although one specimen as short as 38 cm was observed around 2009 in the Philippines) and their conventional range mass hardly ever exceeds the 10 pounds figure (20 kg).
When compared to their mothers however, a startling contrast is observed. They stretch only about one-twentieth (1/20) the average length of their mothers (at 10 meters long) and weigh at least 600 times less their average mass (at 16,000 kg).
Baby whale sharks exhibit many innate biological characteristics. Their growth progress is naturally slow and they attain maturity only at a much later stage in their lifetime. They however grow into impressive lengths and mass and boast an extraordinary extended longitivtiy. We’ll discuss more about these in later sections.
Mating in whale sharks
All living organism in existence today are immediate by-products of asexual or sexual reproduction and baby whale sharks are no exception to this fact.
The concept of mating in whale sharks, particularly the period when they mate and the location where they do so, is still one of the greatest secretes that the depths are keeping away from scientist, but one thing is at least certain, how cartilaginous fishes like sharks and rays generally go about their mating business when it’s nooky time.
Female whale sharks can be distinguished from their male counterparts by the absence of a reproductive organ called the clasper. This organ, which is tube-like in structure and located at the back of the pelvic limbs in males, helps in the seamless transfer of milky sperm from the male testes into the female oviduct: an opening that leads into her eggs.
Right before physical mating occurs (any contact between the genitals of both parties) the male approaches the female and begins to bite, roll and thrash on her until he finally secures her in place either by biting tightly on her pectoral fins or any part of her upper and lower body.
This behavior facilitates a successful and efficient sperm transfer from males into females. Females usually have thick outer coverings (or skin) that helps prevent the holistic bite from causing them any serious and unnecessary injuries.
After the female is firmly stabilized in place, the male proceeds to insert his clasper into her oviduct opening. Next, he releases sperm from his storage area: the testes, and transfers it through the clasper and into the oviduct that leads to the female eggs. The sperm fertilizes the eggs and if everything goes right, litters of individual whale sharks are born.
Female whale sharks have the ability to store bulk of sperm from their mating partners for longer duration. They use this sperm to selectively fertilize their eggs at different phases or whenever they want over prolonged periods. With this habit, female whale sharks can reproduce even without coming in contact with a male partner.
Mode of embryo development
Whale sharks have an ovoviviparous mode of embryonic development, which means that they give birth to litters of live young after successfully laying eggs and hatching them within the boundaries of their utero (inside them).
The other two mode of embryo development found in sharks include the oviparity, laying numerous eggs and fertilizing them outside the mothers utero, usually at the ocean floors, and viviparity, no egg, no hatching, rather the embryo has a direct connection with the mother using a specialized organ called the placenta.
The ovoviviparous nature of whale sharks was confirmed from a 10.6 meter long and 16,000 kg female specimen harpooned 5 kilometers off the east coast of taiwan in 1995.
Upon examination, she had as many as 301 fetal pups ranging between 40 to 70 cm in length within her utero. These fetal pups were all at different stages of development, some still encased within their egg shells while other had emerged and were ready to be deposited into the ocean.
This findings signifies and conjures up the speculation that female whale sharks are able to store up male sperms for longer duration and use them to selectively fertilize their eggs over a prolonged period.
Female whale sharks give birth to a pup litter containing as few as 16 neonates and as much as 300 or even more.
Aside from the protection offered to fetal embryos during their early stges of development, by being preserved within the boundaries of the mother’s utero, no other protection is offered to them after birth.
Newly released young are left out in the scary atmosphere of the oceans to fend for and protect themselves against notorious pelagic predators.
It is suspected that baby whale sharks suffer a high mortality rate during their first few moths after birth; that could be the reason why whale sharks give birth to as many as 301 pups per breeding cycle; to increase the chances of a passing on generations.
What do baby whale sharks eat?
Baby whale sharks feed on small planktonic oragnisim like shrimps, fishes and tunas.
They forage using a method known as filter-feeding, in which they either suck in palnkton rich water into their mouth from a vertical position underneath water, or swim fast across the surface of the ocean ramming planktom rich water into their mouth.
Then, they filter out the water from the prey using specialized organs known as filter pad, and then swallow their entire prey live and whole.
Baby whale sharks have numerous tiny teeth arranged in as much as 300 tooth rows in both the surface of the upper and lower jaw.
Despite this outrageous number of teeth however, baby whale sharks do not use them for any apparent purpose. Their teeth are considered as vestigal stricture; remnant of what used to be the feeding teeth of their ancestors .
Maturity and adulthood
It is suspected that baby whale shark attain maturity at an age between 25 to 30 years, which corresponds roughly to a total body length of 9 meters. Whale sharks can live for upto 130 years and grow their biggest at that age: 20 meters tall and up to 40,000 kg in weight.
More interesting articles
Cite this Article ” (APA Format)
Bunu. M. (2020, June 6). Baby Whale Shark: Everything you should know. Retrieved from http://emborawild.com/baby-whale-shark/