SB Project: Sketches 23 and 24
Here are a couple more sketches. Tomorrow I’ll be posting some recent paid work I’ve been doing – rejected sketches as well as finished images.
Amber snails are sometimes infected by a parasitic flatworm called Leucochloridium paradoxum. The snails are an intermediate host for the flatworms, but the parasitism is most unfortunate for the snails. Once inside a snail’s gut, the flatworm grows long broodsacs full of many free-swimming larvae. The pulsating broodsacs push up into the eye stalks of the snail and with their movement and bright colors they attract the attention of birds. The snail, unable to detect light as it normally could, may wander out of the shade, further increasing its chances of being discovered by a bird. The bird will then peck at the pulsating eye stalks, thinking they are wriggling grubs, and thereby ingest the larvae inside the broodsacs. The flatworms complete their reproductive cycle inside the bird, producing thousands of eggs which the bird then excretes, and more snails consume in the bird’s droppings. Not grossed out yet? Watch this video.
Remoras can swim on their own, but usually attach themselves to larger hosts with their specially evolved dorsal fins. The modified fins create suction, and the remoras are able to ride along with their hosts, benefiting from scraps of food and/or the hosts’ excrement. Remoras associate themselves with a number of large ocean dwellers, such as manta rays, sharks, whales, tuna, sea turtles, and dugong. They are not thought to be parasitic, but instead do not help or harm the host. There may be some species that feed on the host’s parasites, however, which would be considered mutualism rather than commensalism.