2015 Photo Contest, Nature, Stories, 1st prize

Mindsuckers

Photographer

Anand Varma

National Geographic

19 April, 2012

When a male sheep crab (Loxorhynchus grandis) is infected by Heterosaccus californicus, a parasitic barnacle, it stops developing fighting claws, and its abdomen widens, providing a womb for the barnacle to fill with its brood pouch. Nurtured by the crab, the eggs hatch. Thousands of baby barnacles disperse to infect anew.

Many parasites not only feed off their hosts, but appear to manipulate the host’s behavior in a way that is advantageous to the parasite’s life cycle. Recent research indicates that this influence occurs at a genetic level—certain parasite genes seem to be able to take control of the host’s brain. Research has shown that in some cases a single parasite gene is responsible for altering the host’s behavior, though in most instances it is thought that the phenomenon is brought about by a combination of genes.

Many parasites not only feed off their hosts, but appear to manipulate the host’s behavior in a way that is advantageous to the parasite’s life cycle. Recent research indicates that this influence occurs at a genetic level—certain parasite genes seem to be able to take control of the host’s brain. Research has shown that in some cases a single parasite gene is responsible for altering the host’s behavior, though in most instances it is thought that the phenomenon is brought about by a combination of genes.

About

Anand Varma

Anand Varma is a freelance photographer and videographer who grew up in Atlanta, Georgia. He started photographing natural history subjects while studying biology at the Universi...

Background story

When a male sheep crab (Loxorhynchus grandis) is infected by Heterosaccus californicus, a parasitic barnacle, it stops developing fighting claws, and its abdomen widens, providing a womb for the barnacle to fill with its brood pouch. Nurtured by the crab, the eggs hatch. Thousands of baby barnacles disperse to infect anew.

Technical information

Shutter Speed
1/197
Focal length
100.0 mm
F-Stop
16.0
ISO
160
Camera
Canon EOS 5D Mark III

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