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

MAMA RAY,
BABY STINGRAYS BEING BORN,
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 their mother stingray.

Pregnant stingrays move to 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 little stingrays a good start.


Stingrays are born live. They are folded and spindle-shaped upon exiting the cloaca. Their spines are flexible. A sheath covers them to cushion the females during delivery. The sheath sloughs off shortly after birth.


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


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


Female stingrays may safeguard offspring until they mature. Depending upon the species, maturity is achieved between 1 and 5 years of age. Males progress more slowly than females. Birthing may be an annual event.


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


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.


Male stingrays and sharks have two reproductive organs. Paired “claspers” extend toward the tail from each pelvic fin. Only one is used for each mating session. Painful spurs keep it in place during copulation.


Claspers deposit sperm into the cloaca. 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 fertilize eggs in the female cloaca.


Fish make no facial expressions. Actions give clear signs of rage or joy. Children see hints of the motherly care and worry in Mama Ray. She worries about Little Ray's daredevil risk-taking with his determined goal.


Fish seldom give warnings. Like mama dogs, mama rays may charge predators. Both mothers are equipped to defend their pups. Stingrays use venomous stinging barbs. Mama dogs growl and brandish fierce fangs.


Baby sharks receive no parental care. Some arrive live, by viviparous, placental birth. In this form of reproduction, the young develop within the body of the parent. Offspring are highly developed at the time of delivery.


Most fish hatch from eggs. In oviparous species, fertilization is external. Embryos develop within laid eggs. For ovoviviparous species, fertilization is internal and eggs hatch within the adult.


Female sharks seek safe locations to lay eggs. Sharks in the Heterodontidae family, including Port Jackson, Bullhead and Horn Sharks lay spiral-shaped egg cases. They harden in place after females push them into crevices.


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.


Ovoviviparity is more aptly described as histotrophic viviparity. Eggs with shells, membranes or envelopes hatch internally. Uterine histotrophic secretion provides sustenance after yolk depletion.


Internal shark embryos may consume smaller embryos or eggs. From several eggs, one or two of the most fit pups is born. In sharks with two uteruses, intrauterine or interuterine embryophagy and oophagy may occur.


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”.


Being in the wrong place might end poorly. Some mother sharks devour their young. Large sharks and other predators dine on shark pups and smaller species. Low birth and survival rates contribute to loss of these species.


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


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


Bony fish reach adulthood in stages dissimilar to cartilaginous fish. They are called larvae while sustained with yolk-sacs. They become fry once they can feed themselves. Fingerlings have working fins.


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 can swim.


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 from ice floes near the water surface.


Semelparous animals reproduce once. Male octopuses, squid and cuttlefish die after egg fertilization. Females live long enough for birthing. Most fish are iteroparous with multiple reproductive cycles over their lifetimes.


Fathers play important roles. 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.