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 annual baby stingray birth. In The Amazing Flight of Little Ray, Mama Ray represents love, care and protection. Safety at birth gives a good start.
In the Fold? Stingrays are born live. They exit the mother folded like spindles. Their flexible stinging spines have sheath coverings to cushion the mothers 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 after delivery.
Playing it Cool? Newborn stingray pups sink to the ocean floor, then unfold to begin swim practice and strength training. In a few days, they develop consistent and powerful strokes. They begin hunting.
Wave Action Most stingrays live in coastal ocean environments, with hazardous Rip Currents. Waves break near shore, then return to sea in strong streams, sweeping some family members out to sea.
Transparency? Baby stingrays are quite transparent. This helps them hide. Their Big Skate cousins, Raja Binoculata, remain pale in adulthood. Visible insides and human-like “faces” make them aquarium attractions.
Celebrity Babies? Mature stingrays have up to 12 pups in a litter. The first pregnancy may result in one pup. Inexperienced mothers gain practice by safeguarding the earliest babies in small numbers.
Matriarchs? Compared to males of the same age, female stingrays are considerably longer and wider in disk width. Their impressive size strikes fear in potential predators, reducing the risk of attacks.
Perfect World? Female stingrays of some species 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.
Great Shapes? Giant mantas use size as defense. They can do head butts or body slams. They have no stingers. Little is known about these large, primitive fish in the Mobulidae family of ocean and devil rays.
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.
Sanctuary? In 2018, mantas were listed under the U.S. Endangered Species Act. Critical habitat conservation designations for a newly-discovered Florida manta nursery habitat are recommended to protect this species.
Manta Ray Nurseries? There are three known manta ray nurseries in the world. One is along the Palm Beach County coast of Florida. Two other nurseries are located in the Gulf of Mexico and in Indonesia.
Juvenile Studies? Observations of large numbers of juvenile Giant Oceanic Mantas may reveal 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 and no predators. However, they are located in busy fishing and tourist areas. Almost half of the Florida juveniles had fishing equipment wounds.
Delayed Parenthood? Greenland Sharks do not reach sexual maturity until they are over the age of one hundred years. Unlike animals 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 hatch within the mother. Most sharks are cannibals.
Shark-Eat-Shark? Per Marine Science Professor Mark Meekan, “It's not just one rogue shark attacking other sharks or even one species of shark attacking other sharks, it's lots of different sharks turning on each other.”
Sharklet? This term does not refer to shark pups. The “-let” word ending may be used to indicate young animals, like eaglets. Sharklet is the name of an Airbus aircraft wing-tip extension designed for fuel efficiency.
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.
Rosy Futures? Being in the wrong place ends poorly. Some mother fish eat their young. Large predators dine on smaller sharks, rays and bony fish. Low birth and survival rates contribute to losses detailed in No fishing.
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 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-formed pups.
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 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.
Core? The yolk is the nutritious part of an egg. All bony fish, some sharks and some rays have yolk sacs at some stage of life. All oviparous fish retain the sac after hatching. Sharks with placentas have no egg yolks.
Growth Plan? Bony fish reach adulthood in stages, but never as “pups”. They are larvae while supported by yolk-sacs. They become fry when they feed on their own. Fingerlings have working fins for hunting.
Mother Stingrays & Sharks
Multipurpose? Female stingrays and sharks have a single reproductive opening. Called the cloaca, it is the channel for birth, feces and urine. Bony fish have no cloaca. It occurs in birds, reptiles and amphibians.
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.
Poker Face? Fish make no facial expressions. Actions indicate rage or calm. Children see hints of motherly concern in Mama Ray. She frets over Little Ray's daredevil risk-taking to soar above all Flying Stingrays.
Father Stingrays & 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.
Leg Up? The claspers are leg-like appendages. They help the males mount the females. The similarity to legs ends here. Claspers did not evolve from legs. Whales are mammals with hip bones to aid in mating.
Strange Timing? Mating may occur several months before a female ovulates. Unlike some mammals, such as cats, rabbits and camels, the sperm does not start ovulation. Female stingrays ovulate in the spring.
Making Stingray Babies & Baby Sharks
Current Affair? Courtship is aggressive. More than one male may chase down a willing or unwilling female. During mating, 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 makes females cooperative.
Soft Touch? Science writer Mary Bates brought shark hypnosis to Wired. Humans should not rely fully upon this natural calming technique. Sharks quickly regain mobility and tail-whips or bites return.
Multiple Paternity? Sharks and stingrays from the same litter may have different fathers. Stingrays and some sharks have two uteruses in which to hold embryos from more than one male until birth.
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. Deadly infections may develop from these impactions.
Mind of a Chef? All rays give aplacental, ovoviviparous birth. There is no placenta for nutrition, oxygenation or waste exchange. Mammal-like shark placentas tie some embryos to their mothers via umbilical cords.
Stingray & Shark Embryos
No Egg Sac? Royal Society Publishing released 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.”
No Attachment? Embryonic oxygen and nutrient intake observed in the referenced manta ray study likely occurs in all ovoviviparous Elasmobranch embryos having no direct connection with the mother.
All Covered? Ovoviviparous, or histotrophic viviparous stingray embryos absorb nutrients. After yolk depletion, uterine histotrophic secretions sustain life. Offspring are highly developed at the time of live delivery.
In the Clear? Anadromous fish spend most of their life in saltwater. They return to freshwater to spawn. Salmon are widely known for annual migrations of males and females for reproductive purposes.
Splitting Image? Catadromous fish are born at sea, but they spend most of their adult lives in fresh water. They return to saltwater for spawning. American and European eels are examples of this 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.
Inside Job? In sharks with two uteruses, intrauterine or interuterine embryophagy or oophagy may occur; embryos consume smaller embryos or eggs. From several eggs, one or two pups may survive.
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”. They prefer mild coastal waters. The best-known frigid water cubs are baby polar bears. Deep-ocean sharks leave surface-dwelling seals to these Arctic bears.
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.
Altricial Species? Primate, kangaroo, cat, dog, and human newborns have fully-formed appendages, skin and hair. Physically advanced, but immobile and mentally helpless at birth, they need long periods of care.
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.
Sticking Point? Pity the poor angler fish female. She cannot shake the six or more males that permanently fuse to her body. These parasites depend upon her for life-supporting nutrients. Without her, they would die.
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 a rarity.
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.
Survival to Adulthood
Calling the Shots? Male seahorses fertilize and carry eggs in pouches. Fully-developed fry swim to freedom. One type of seahorse mates for life. Ariidae catfish males orally incubate eggs until the fry can swim.
Rare Exception? Clownfish are model 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.
Goof Offs? Dolphins love to play. Playtime helps dolphin calves practice and strengthen swimming and social skills. They are friendly to humans, but they need to stay wild, so they don't become easy targets for crime.