Extremely rare to have two conjoined twins within 24 hours
During a routine experiment, researchers at GEOMAR Helmholtz Centre for Ocean Research Kiel made a very rare discovery: a pair of newborn broadnosed pipefish that turned out to be conjoined twins.
The researchers Dr Olivia Roth and Maude Poirier had wanted to find out how broadnosed pipefish in the Baltic Sea dealt with changes in the salinity of seawater and whether their coping abilities would be passed on to their offspring. However, when their test subjects gave birth recently, the two researchers discovered two conjoined twins amongst the new brood.
“Although I have been performing such experiments for seven years, this is something that has never happened before,” said Dr Roth, a Junior Group Leader in the area of marine ecology at GEOMAR. Since the animals have been born under normal conditions that occur here in the Kiel Fjord, it seems to just be coincidence for Dr. Roth.
The two young pipefish have already gone through several weeks of growth, so they are no longer in the form of larvae.
Conjoined twins are identical twins whose fertilised egg did not completely separate when in the womb (or the brood pouch, in the case of the pipefish). The probability of finding two conjoined twins within 24 hours is extremely low.
In humans, it occurs in every 200,000 pregnancies. Less than half of such embryos survive the pregnancy, with one of the twins being stillborn. The odds of both twins surviving the pregnancy are one in a million. In the animal kingdom, conjoined twins are rarely encountered; even if the newborns were to survive the birth, they are often rejected by the parents and have trouble when moving around and foraging for food.
Further information: www.geomar.de