Photograph
by JERRY MONKMAN, MYN/NATURE PICTURE LIBRARY
To a lobster
couple, this is normal sex:
For days the female squirts urine into the den of
her desired mate. Beguiled by the scent, he lets her move in. Foreplay—stroking each other with
antennae and with feet covered in taste receptors—lasts several days.
Once she’s convinced that
he’ll protect her, the female disrobes,
slowly shedding both her
hard shell and the pouch where she had banked sperm from a prior mate. Molting
leaves her in a perilously soft new shell, so he stands
guard for the half hour it takes to harden. Then, supported by his claw legs, he suspends himself above her and lifts
her to face him, cradling her in his legs. Her new shell has a new sperm pouch; he thrusts a packet of
sperm into it using appendages called gonopods. The deed is done.
As soon as
one mate leaves, the male will welcome another. The female, meanwhile, will use the sperm packet
to fertilize thousands of eggs, which she’ll carry under her tail for about a
year until the larvae hatch.
But climate
change is threatening this babymaking process, says Diane Cowan, founder of the
Lobster Conservancy.
When water is warm, lobsters put their energy into
growing; when it’s cold—winter water temperatures in the 30s Fahrenheit—they put that energy into making eggs and sperm, Cowan
says. If climate change shortens that cold period, “they’ll produce fewer gametes. And if
it’s steadily too warm, they
just won’t produce. No eggs.
No sperm. No lobsters.”
yellow : subject
red : verb
(This
story appears in the July 2017 issue
of National Geographic secret antartica)
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