http://www.scientificamerican.com/article.cfm?id=how-remora-got-its-sucking-disk
Summary:
Remoras are a family of eight species of tropical fish. Another name for the remora is the shark sucker. Remoras get their name because of the sucking disks that they have on top of their head. They use that disk to latch onto other creatures, including sharks, fishes, turtles, divers, and ships. Scientists have finally discovered where the sucking disks came from. A group of ichthyologists (fish experts) injected red dye into the bones of remora larvae and other fishes. They did this so that they could watch them grow. Up until a certain point, the dorsal fin and the supporting skeleton developed in the same way in remoras as it did in the other fishes. Then the dorsal fin bones in the remora expanded and shifted up towards its head. When the juvenile remora grew to 30 mm long, it had grown a 2 mm long sucking disk.
NOS Themes
- Science is collaborative- "ichthyologists"
- Science is based on evidence- "ichthyologists injected red dye into the bones of larval remoras and other fishes so they could watch them grow."
It would be interesting to find out if their sucking disk is an adaptation, and if it is when they got it. Remoras don't grow to be very big, only about 34in, so they could have adapted so they could get food from their hosts.
ReplyDeleteLink:http://www.bbc.co.uk/nature/blueplanet/factfiles/fish/remora_bg.shtml