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)
This Mother's Day, Mama Ray celebrates making stingray babies, baby stingrays being born, survival to adulthood after baby stingray birth and tells 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 like spindles. Their flexible stinging spines have sheath coverings to cushion the females during birthing. These slough off shortly after birth.
Nightlife? Wild stingrays are nocturnal. Birth usually occurs at night. Gestation averages 9-to-12 months. As the mother stingray goes into labor, males gather to impregnate her immediately after delivery.
Playing it Cool? Newborn stingray pups sink to the ocean floor, then unfold to begin swim practice and strength training. It takes a few days to develop consistent and powerful strokes. This accomplished, they begin hunting.
Celebrity Babies? Mature stingrays have up to 12 pups in a litter. The first pregnancy may result in one pampered pup. Inexperienced mothers gain initial practice by safeguarding the earliest babies in small numbers.
Perfect World? Some species of female stingrays and all discus fish care for their young until they can fend for themselves. Stingray maturity is achieved from 1-to-5 years of age. Females progress faster than males.
Lucky Stars? Human children may get help from both parents. Female deep-water ocean stingrays and mantas leave at birth. Males depart immediately after mating. Sea creatures rarely receive dual parental oversight.
Big Cousins? Manta rays delay breeding until they are 8-10 years old. Once they come of age, they have a pup or two every few years. It is difficult for them to keep up with over-fishing and injury to this species.
Manta Ray Nurseries? A third known manta ray nursery was found along the coast of Palm Beach County Florida. Only two other nurseries are known to exist. One is in the Gulf of Mexico. Another is in Indonesia.
Juvenile Studies? Observations of large concentrations of juvenile Giant Oceanic Mantas may help discover birthing locations, lifespans, mating selection criteria, and how they give birth. These facts are little known.
Nursery Conditions? The nurseries tend to have abundant food supplies and no predators. However, they are located in busy fishing and tourist areas. Almost half of the Florida juveniles had fishing equipment wounds.
Sanctuary? In 2018, mantas were listed under the U.S. Endangered Species Act. Critical habitat conservation designations for the newly-discovered Florida manta nursery habitat are recommended for protection of this species.
Delayed Parenthood? Greenland Sharks do not reach sexual maturity until they are well over the age of one hundred years. Unlike organisms that reproduce early and often, these sharks do not quickly replenish their species.
Wild at Heart? Sharks receive no parental care. Some arrive by viviparous, or live, placental birth. For ovoviviparous sharks, fertilization is internal. Eggs with enveloping membranes hatch within the parent.
Precocial Species? Highly-developed cartilaginous rays and sharks can fully care for themselves at birth. Few other fish and no mollusks are born into the ocean as fully-formed miniature adults.
Fertile Ground? Sharks do not spawn like other fish. Salmon make long migrations to meet up for this external form of procreation in water. Gamete is another name for a mature male sperm or female egg reproductive cell.
Jewelry Box? Egg-laying sharks produce 10-to-200 eggs. These are protected by leathery cases called “mermaid's purses”. Yolks sustain embryos to an advanced stage of development. They hatch as fully-developed pups.
Multiple Yolks? The egg cases surrounding the eggs of oviparous sharks and skates typically contain one embryo. This is a normal ovary pattern for most egg-laying animals. Skate egg cases often contain multiple embryos.
All the Angles? Female Port Jackson, Bullhead and Horn sharks in the Heterodontidae family lay spiral-shaped egg cases. These harden in place after the females push them into crevices for safe-keeping.
Multiple Paternity? Sharks and stingrays from the same litter may have different fathers. More than one male can inseminate a female. Stingrays and some sharks have two uteruses in which to hold their embryos until birth.
Inside Job? In sharks with two uteruses, intrauterine or interuterine embryophagy or oophagy may occur. Internal shark embryos often consume smaller embryos or eggs. From several eggs, one or two pups may survive.
Maze? Fish can suffer life-threatening egg binding. Obesity, malnutrition, stress or small body size can result in failure of eggs to exit the reproductive tract or be absorbed. Deadly infections may develop from these impactions.
Rosy Futures? Being in the wrong place ends poorly. Some mother fish devour their young. Large predators dine on smaller sharks, rays and bony fish. Low birth and survival rates contribute to losses detailed in No fishing.
Induced Labor? ElSevier B.V. Science Direct reported findings of sharks and rays going into “capture-induced labor”. Premature births, or abortions, brought on by the stress of capture augment fishing threats against them.
Mother Stingrays and Sharks:
Mind of a Chef? All rays give aplacental, ovoviviparous birth. There is no placental connection for nutrition, oxygenation or waste exchange. Mammal-like shark placentas tie some embryos to their mothers via umbilical cords.
Egg Sac? Royal Society Publishing found Live-bearing manta ray: how the embryo acquires oxygen without placenta and umbilical cord. “The manta ray embryo takes in uterine fluid by buccal-pumping.” There is no yolk sac.
No Attachment? Embryonic oxygen and nutrient intake observed in the referenced manta ray study likely occurs in all ovoviviparous Elasmobranchs embryos having no direct connection with the mother.
The yolk is the nutrient-bearing part of an egg. All bony fish, some sharks and some rays have yolk sacs at some stage of development. All oviparous fish retain the sac after hatching. Sharks with placentas have no egg yolks.
All Covered? Ovoviviparous, or histotrophic viviparous stingray embryos absorb nutrients. After yolk depletion, uterine histotrophic secretions provide sustenance. Offspring are highly developed at the time of live delivery.
Making Stingray Babies or Baby Sharks:
Tough Love? Male stingrays and sharks have two reproductive organs. Paired claspers extend toward the tail from each pelvic fin. One clasper with painful spurs grasps the female during each mating session.
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.
Leg Up? The claspers are leg-like appendages. They do help the males mount the females, but the similarity to legs stops here. Claspers did not evolve from legs. Whales are mammals with hip bones to aid in mating.
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.
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 females 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 mobility. Tail-whips or bites return with vigor.
Survival to Adulthood:
Cannibals? Some female animals kill their mates. Female octopuses, praying mantises and spiders sacrifice their mates as last suppers. Maternal care for offspring is common. Matriphagy, or mother-eating is an ocean rarity.
Poker Face? Fish make no facial expressions. Actions indicate rage or calm. Children see hints of motherly care and worry in Mama Ray. She frets over 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 come equipped to defend their pups. Stingrays wield venomous stingers. Mama dogs brandish fierce fangs.
Growth Plan? Bony fish reach adulthood in stages, but never as “pups”. They are called larvae while sustained by yolk-sacs. They become fry once they feed independently. Fingerlings have working fins for active hunting.
In the Clear? Anadromous fish spend most of their life in saltwater. They return to freshwater to spawn. Salmon are widely known for long annual migrations to bring males and females together for reproductive purposes.
Splitting Image? Catadromous fish are born at sea, but they spend most of their adult lives in fresh water. They migrate back to saltwater for spawning. American eels and European eels are examples of this uncommon life cycle.
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.
Manifest Destiny? Semelparous animals reproduce only once. Male octopuses, eels, squids, salmon and cuttlefish die after spawning. Females may live long enough to guard the eggs until they hatch.
Long-Lived? Most fish are iteroparous, with multiple reproductive cycles in their lifetimes. Animals with this life cycle typically produce fewer offspring over longer lifespans. Parental care may be extended to the young.
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.
Sharklet? This term does not refer to shark pups. The “-let” word ending often is used to indicate young animals, like eaglets. Sharklet is the name of an Airbus aircraft vertical wing-tip extension designed for fuel efficiency.
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? Adult bull sharks are called “cub sharks”, but they prefer mild coastal waters. The best-known frigid water cubs are baby polar bears. Deep-ocean sharks in their climate leave surface-dwelling seals to these bears.
Altricial Species? Human newborns look fully developed, with arms, legs, skin and hair. Physically immobile and mentally helpless at birth, they require long periods of care.
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. Ariidae catfish males orally incubate eggs until the fry can swim.
Rare Exception? Clownfish are exceptional oceanic parents. They work together to transform a stinging anemone into a clean and welcoming nest. They tend to the eggs and hatching babies to improve survival chances.