Friday, December 08, 2006

Parental care

The phrase parental care often brings up images of some mammal cuddling its furry large eyed child to its bosom. It seems the epitome of bonding between parent and child and visual images abound, like Raghu Rai's the small hand within the large hand.

Yet some of the most amazing stories of parental care actually occur within the so called 'lower' organisms. I'll tell you about the most amazing one. The now extinct gastric brooding frog female swallows her externally fertilized eggs and they remain in her stomach for weeks before they are old enough to brave the world on their own. The frog does not eat the whole time!

Still, invertebrates? Really? Can somethings that 'low' actually show such 'evolved' behaviour. I think people underestimate insects. Even those that don't would perhaps find it hard to like cockroaches. Yet here is a description of cockroach brood care from an abstract of a technical paper.
" Cockroaches show the entire range of reproductive modes: oviparous, ovoviviparous, viviparous, and intermediate stages. Postparturition parental care is likewise diverse, ranging from species in which females remain with neonates for a few hours, to biparental care that lasts several years and includes feeding the offspring on bodily fluids in a nest. "
In fact these insects are called sub-social and these behaviours are believed to be precursors to the more admired eusociality observed in some other insects. Termites the well known superorganisms, of the social insect world are phylogenetically quite close to roaches. So look closer before turning away in disgust the next time!

(For people who wanted to know more tech stuff about the image, it was shot in the daytime in IISc, in Sept 2005. f32, 1/60 with a cheapie manual ring flash the vivitar 5000, Nikon D70 and MicroNikkor 105mm.)

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