A nest excavation carried out by the Juara Turtle Project (JTP) in Tioman, Malaysia, revealed an unusual find on Facebook last week as conservation workers found two turtles sharing an egg. Twinning in sea turtles is a rare occurrence and one whose triggers and survival implications aren’t fully understood. As such, while the hatchlings in this incidence never made it out of the egg, their existence makes for an intriguing academic finding.
The twins were green turtles (Chelonia mydas), just one of several species who schlep it back to Juara on Tioman Island in Malaysia to lay eggs on the sandy beach. Turtles hatching here are afforded a head start in life thanks to JTP which aims to support the global turtle population by protecting egg clutches, studying hatchlings, and facilitating their release. JTP also work with egg collectors and pay them a fair wage to support the project as a sustainable alternative to poaching, benefiting the local community and the animals at the same time.
Once a turtle lays their eggs, JTP will carefully remove them from the nest and rebury them in a protected shelter (the hatchery) so they can develop free from both natural and man-made threats. Once a clutch of hatchlings emerges, the team gather data on them before releasing them into the ocean. After a few days, they excavate the nest for “stragglers” (turtles still alive who missed the boat in wriggling surface-side) and dead embryos to gain insights into why some nests are more successful than others.
During a recent excavation, the team came across a set of twins sharing an egg, something which JTP says is rare but has been reported across the globe.
“There are two general distinctions in sea turtle twinning cases,” said JTP to IFLScience. “The hatchlings could either be fully separated twins or conjoined twins. The recent discovery at JTP was a case of fully separated green turtle twins of equal size, sharing a common yolk sac. The twins were among the 5 unhatched eggs out of a clutch of 105 eggs relocated into our hatchery.”
Unfortunately, in this instance, the hatchling twins hadn’t survived which may have been due to two turtles competing for resources inside the egg. That said, the twins had made it to a late stage of development, and two turtles emerging alive from a single egg isn’t unheard of, with some even surviving as conjoined twins.
As JTP have discovered over the years, you never know who’s going to emerge from (or what you’re going to find inside) a turtle egg.
“JTP has recorded several cases of albinism and leucism in hatchlings over the years – both of which involve genetic factors playing a key role resulting in the pigmentation anomalies,” they said. “Additionally, we have also had a case of conjoined twins where hatchlings with two heads shared a common body with a single pair of front and hind flippers.”
Turtles across the globe are currently under threat from illegal trade, fishery bycatch, loss of nesting grounds, marine pollution, and climate change, but there’s a lot you can do to help. Many projects, including JTP, take on volunteers and you can support their work remotely through sponsoring a nest or making donations. Making small, sustainable changes to your plastic consumption and behavior as a tourist can also make a big difference, keeping the turtle’s environment free from trash and respecting their space by not touching any turtles you see in the wild.
For more information on how you can support turtles in the wild, visit the Juara Turtle Project website.