Little Ray and Mama Ray displayed at 50% of viewport width
May 2019 by V. R. Duin

MAMA RAY | BABY STINGRAY BIRTH

Knowing Little Ray to be brave and young,
Mama Ray managed to hold her tongue.
After all, her boy would never ever know
what he could do without giving things a go.
(The Amazing Flight of Little Ray)

In this month of motherhood, Mama Ray tells about baby stingrays being born, survival to adulthood after baby stingray birth and how long stingray babies stay with mother stingrays.

Stingrays Being Born

Starlet? Pregnant stingrays seek low-risk areas for baby stingray birth. In The Amazing Flight of Little Ray, Mama Ray represents love, care and protection. Safety at birth gives a good start. Birthing typically is annual.


In the Fold? Stingrays are born live. They exit the mother folded and spindle-shaped. Their spines are flexible with a sheath covering to cushion the females during birthing. The sheath sloughs off shortly after birth.


Nightlife? Stingrays in the wild are nocturnal. Birth usually occurs at night. As the mother stingray goes into labor, males assemble to impregnate her immediately after delivery. The gestation period averages 9 to 12 months.


Partnership? As females mature, there can be up to twelve pups in a “litter”. Female deep-water ocean stingrays and mantas leave at birth. Males depart immediately after mating. The first pregnancy often gives birth to one “pup”.


Playing it Cool? Newborn stingray pups sink to the ocean floor, unfold and begin practicing their swimming. It takes a few days for them to develop a consistent and powerful stroke. This accomplished, they begin hunting.


Growth Plan? Bony fish reach adulthood in stages unlike rays and sharks. They are called larvae while sustained with yolk-sacs. They become fry when are on their own. Fingerlings have working fins for hunting.


Perfect World? Female stingrays may safeguard their offspring. Discus fish also care for their young. Depending upon the species, stingray maturity is achieved between 1 and 5 years of age. Females progress faster than males.

Mother Stingrays and Sharks

Wild at heart? Sharks receive no parental care. Some arrive live, by viviparous, placental birth. For ovoviviparous stingrays, fertilization is internal. Eggs with shells, membranes or envelopes hatch within the parent.


Forward Thinking? Some fish are hermaphrodites with both male and female sex organs. Others alternate between sexes. Most fish are oviparous, developing within and hatching from externally fertilized, laid eggs.


Mind of a Chef? Stingrays give aplacental, ovoviviparous birth. Viviparous sharks have placentas for nutrition and waste exchange with the mother. Their mammal-like umbilical cords attach the embryo to the placenta.


All Covered? Ovoviviparity is more aptly described as histotrophic viviparity. Uterine histotrophic secretion provides sustenance after yolk depletion. Offspring are highly developed at the time of live delivery.


Inside Job? Internal shark embryos may consume smaller embryos or eggs. From several eggs, one or two fit pups surge forth. In sharks with two uteruses, intrauterine or interuterine embryophagy and oophagy may occur.


Jewelry Box? Egg-laying sharks produce 10 to 200 eggs. Eggs are protected by leathery cases called “mermaid's purses”. Yolks sustain the embryos to an advanced stage of development. They hatch as fully-developed “pups”.


All the Angles? Female shark in the Heterodontidae family, including Port Jackson, Bullhead and Horn Sharks lay spiral-shaped egg cases. These harden in place after the females push them into crevices for safe-keeping.


Maze? Fish can suffer life-threatening egg binding. Obesity, malnutrition, stress or small body size may result in failure of eggs to exit the reproductive tract or be absorbed. Deadly infection may progress with egg impactions.

Making Stingray Babies and Baby Sharks

Tough Love? Male stingrays and sharks have two reproductive organs. Paired claspers extend toward the tail from each pelvic fin. One appendage is used for each mating session. Painful spurs grasp the female for copulation.


Multipurpose? Female stingrays and sharks have a single reproductive opening. Called the cloaca, it serves as the channel for birth, feces and urine. Bony fish have no cloaca. It is common in birds, reptiles and amphibians.


Current Affair? Courtship is aggressive. More than one male may chase down a willing or unwilling female. During copulation, the male arches his back and stretches a clasper forward to place sperm inside the female cloaca.


Strange Timing? Mating may occur several months before the females ovulate. Unlike some mammalian species, including cats, rabbits and camels, the sperm does not induce ovulation. Female stingrays ovulate in the Spring.


Funny Business? Tonic immobility aids reproduction. This temporary state of paralysis may be prompted by flipping sharks and rays over. Enhanced by belly rubs, a 15-minute trance-like state helps render sharks cooperative.


Soft touch? Science writer Mary Bates brought shark “hypnosis” to Wired. Humans should not rely fully upon this natural calming technique. Aroused sharks quickly regain normalcy. Tail-whips or bites may be reality-checks.

Survival to Adulthood

Pokerface? Fish make no facial expressions. Actions indicate rage or calm. Children see hints of motherly care and worry in Mama Ray. She worries about Little Ray's daredevil risk-taking to soar above all Flying Stingrays.


Loud and Proud? Fish seldom give warnings. Mama dogs and mama rays may charge at intruders. Both mothers are equipped to defend their pups. Stingrays wield venomous stingers. Mama dogs brandish fierce fangs.


Rosy Futures? Being in the wrong place ends poorly. Mother sharks may devour their young. Large predators dine on shark pups and smaller rays. Low birth and survival rates contribute to losses detailed in No fishing.


Great Shapes? Giant mantas use size as defense. They can make head butts or body slams. They have no venomous stingers. Little is known about these large, primitive fish in the Mobulidae family of ocean and devil rays.


Free Range? No kittens roam the seas. Oviparous catsharks hatch as “pups”. Catsharks (Scyliorhinidae) and dogfish (Squaliformes) look similar. Ovoviviparous dogfish lack the anal fins present in catsharks.


Cold Calling? The best-known cubs of ocean life are polar bear babies. Humans are their only predators. Sharks in frigid polar bear country hunt at great depths. Bears catch seals from land or ice floes near the water surface.


Manifest Destiny? Semelparous animals reproduce once. Male octopuses, squid and cuttlefish die after egg fertilization. Females live until birthing. Most fish are iteroparous with multiple reproductive cycles in their lifetimes.


Calling the Shots? Male seahorses fertilize and carry eggs in pouches. Fully developed fry are released into independence. One type of seahorse mates for life. Male ariid catfish orally incubate eggs until the fry are able to swim.


Rare Role Models? Few fish and no mollusks are born into the ocean as fully-formed miniature adults. Children on land may get help from both parents. Sea creatures are lucky to have any oversight from one parent.