Hendersonville – Charlotte the Stingray is pregnant after eight years with no other rays in Team ECCO’s popular aquarium in Downtown Hendersonville.
The absence of males of her species makes people wonder how she got pregnant. The very likely answer is asexual self-propagation, called parthenogenesis or “virgin birth,” Brenda Ramer said. She founded non-profit Team ECCO in 2001, and still runs it. Since 2011, it has operated the Aquarium and Shark Lab at 511 N. Main St. in Hendersonville.
Ramer explained that it is medically possible for round stingrays such as Charlotte to self-multiply, but uncommon — especially for those in captivity.
Round Ray Rarity
“We’re told that Charlotte is the only (Southern) California round stingray in captivity” to be pregnant on her own, Ramer said.
Female sharks self-multiply including TEAM ECCO’s Epa, a banded bamboo shark. She laid twin eggs last Saturday, has laid 900 eggs in the last nine years, and several embryos developed from parthenogenesis, Ramer noted.
In parthenogenesis, unfertilized eggs develop without a male’s DNA. Scientific journals explain that the mother’s reproductive cycle mimics sexual reproduction. An egg fuses with a “polar body,” a cell produced during egg creation. The mother’s nuclei or reproductive gametes join together. This rare fusion triggers cell division, creating an embryo inside the uterus.
The resulting ray offspring are extremely likely to be females and closely resemble the mother — but not as exact DNA clones, Ramer told the Tribune.
The Charlotte intrigue intensified with talk of one of the five young sharks in her huge 2,200-gallon tank possibly fathering the offspring, and Charlotte having markings of a shark trying to mate her. Marine biology experts dismiss this as anatomically impossible, with DNA incompatibility. Any shark attempt to mate with Charlotte might have instead sparked her self-reproducing mood. Charlotte isn’t saying.
Ramer, a former teacher, keeps up with oceanic findings and contributes to them. Ramer said that revenue helps Team ECCO “continue our research in elasmobranch (stingray) parthenogenesis” and general “ocean education and conservation.”
‘Incredible Journey’
Charlotte’s live birthing is greatly anticipated. Ramer said if she gets to witness it, that’d be “phenomenal! This has been an incredible journey. We are still patiently awaiting Charlotte’s delivery.“
Charlotte might deliver her young any day, or weeks from now. Gestation lasts three to four months for mated rays in the wild, but might vary greatly for a captive round ray lacking social interaction with a mate.
Hump Back
Very interestingly, California round rays carry their young in a hump on the back, Ramer pointed out. Proof of Charlotte’s pregnancy was from an ultrasound taken four months ago over concern that a lump in her back was cancerous. It showed developing eggs, Ramer said. Surprise! ultrasound performed. It showed the shape of one cub “rolled up, like a cigarette” within Charlotte’s back, Ramer said.
Mated rays typically carry three or four pups in their pregnancies, Ramer said. Last Saturday, she noted that the latest “ultrasound we sent to our colleagues looked good. There were no signs of any distress.”
Rays typically bathe the embryo in uterine milk once the yolk sac is used up. Charlotte will deliver her young through her birth canal. They will be put into a nursery tank.
Active Motion, Appetite
Charlotte kept swimming laps when the Tribune was there. Ramer said that the prized ray has not shied from larger than usual crowds. Visitors are still allowed to get up to Charlotte’s tank, but are encouraged to move slowly. They can take still photos without flash, but not video.
“Charlotte has rested well, and hasn’t changed her diet,” Ramer said. Kinsley Boyette, the aquarium’s assistant director, submerges into the tank to feed Charlotte. She said that Charlotte’s menu varies daily, providing a broad diet. The ray tends to gobble shrimp and silverside fish the most. She also digests scallops, mussels and crawfish from a small tub.
One researcher playfully called ray pups “ravioli pasta with eyeballs.” Rays are boneless, flat and wide like an oceanic ray. They swim fluidly by flapping side wing-like fins. Pups are born with a venomous tail.
Round rays are sexually mature at about age four. They typically live for 15–24 years. Charlotte is estimated to be ten years old, Ramer said. She extends two feet “from nose to tail fin.” Her two eyes stand out atop her flying saucer-like, grayish-brown body. Round rays use electro-sensors to detect prey and predators.
Featured Attraction
The aquarium was closed for the winter. It reopened in mid-February. The Charlotte craze promptly struck. Daily visitors soared from the usual 50-75 to about 200, Ramer said. The capacity has not been reduced. But people need to buy admission at the door only. They typically wait in line for a half-hour, hour, or longer.
Several downtown establishments are also busier than normal with spill-over patronage.
The Epic Consulting Group in Arizona is handling Charlotte’s publicity. Its CEO, Hendersonville native Kate Foley, told the Tribune that “we have been so thrilled to see all the love and support for Charlotte in the community and across the world… Our goal is to educate, and create conversations around marine biology.”
The Aquarium and Shark Lab is open to the general public Wednesday–Friday, 1-4 p.m. and 12:30-4 p.m. on Saturdays. Admission fees include $7.50 per adult aged 5-65. Check teamecco.org for Charlotte updates.