Press report.
Slimy leeches are devoted parents
Sydney, July 2 Reuters
Australian study a first to show the invertebrate has similar parenting
behaviour to birds and mammals
You wouldn't guess it by looking at them, but some species of leeches brood
like birds and mammals, carrying their new-borns and nurturing their young.
The Australian leech, Helobdella papillornata, is the first known example of
an invertebrate caring for its young into maturity, said evolutionary
biologist Fred Govedich, at Australia's Monash University.
"Although the word leech is often considered synonymous with selfishness and
exploitation, many leeches are devoted parents," Govedich said on Friday.
A Monash study of the Australian leech has been found it carries its young for
up to six weeks after hatching, gathers food and protects them from predators.
The leeches also ferry their offspring to new territories where they will be
safe and well fed after they leave the parent.
The Helobdella papillornata leech gathers in groups of up to 50 leeches and
will provide food to the young of other leeches.
"The findings... introduce an interesting new angle for evolutionary
biologists to consider when attempting to explain how parental care has
evolved," Govedich said. "It is fascinating that an invertebrate is displaying
vertebrate-like parenting."
Govedich said the other interesting aspect of parenting leeches is that
leeches are hermaphrodites but display the parenting behaviours usually
associated with species which have separate sexes.
There are between 700 and 1000 species of leech worldwide.
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