"Pregnant" Fish Fathers Suck the Life From Their Young

"Pregnant" Fish Fathers Suck the Life From Their Young"

Matt Kaplan
for National Geographic News

December 21, 2009
With the fathers taking on the responsibility of "gestating" their young, the story of pipefish reproduction is among the more heartwarming in biology.
Well, it was.

A new study shows that "pregnant" pipefish fathers actually suck the life out of some of their own offspring.
Pipefish are long, slender, upright-swimming seahorse cousins that tend to live in warm seas among sea grasses. (Related: "Seahorse Fathers Take Reins in Childbirth.")
After conception, the female pipefish passes the hundred or so fertilized eggs to the male. Dad carries and—via specialized blood vessels—nourishes them in a small pouch until they emerge as fully functional baby pipefish.
So far, so good. But researchers studying broad-nosed pipefish recently noticed that some or all embryos tend to completely disappear while in Dad's care.
Study co-author Gry Sagebakken and colleagues thought the developing embryos were probably taking nutrients from one another somehow.
On the other hand, "we suspected paternal nutrient uptake was an option, but it was not our first guess," Sagebakken, a doctoral student in animal ecology at Sweden's University of Gothenburg, told National Geographic News.
http://news.nationalgeograp...young.html