BIS2C_Lect30_Ward_Annelida_ppt

BIS2C_Lect30_Ward_Annelida_ppt - BIS2C Winter 2012 (Ward)...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 BIS2C Winter 2012 (Ward) Lecture 30. Annelida Today’s lecture (9 March) Mollusca concluded (nudibranchs, cephalopods) introduction to Annelida major features biology within-group diversity Monday’s lectures Arthropoda Nematocyst-stealing nudibranchs some sea slugs ingest cnidarian tissue and store undischarged nematocysts in elongate protrusions on their back – ready to fire the sea slug thus expropriates the defensive mechanism of another animal Solar-powered sea slugs certain sea slugs feed on algae they digest most algal tissue but sequester the chloroplasts in their in their body, where they continue to function kleptoplasty: the stealing of plastids for use as photosynthetic machines Sacoglossan, Placida cf. dendritica , showing the green network of ducts which contain the green chloroplasts from its algal food. From: www.seaslugforum.net Solar-powered sea slugs sequester alga-derived chloroplasts for use as photosynthetic machines how do they accomplish this, given that the functioning of such organelles in algae requires many nuclear-encoded genes? The sea slug has acquired one or more nuclear-encoded algal genes in its own genome: LGT between in its own genome: LGT between two eukaryotes! Ref.: Rumpho et al. 2008. Proc. Natl. Acad. Sci. USA 105:17867-17871. Cephalopods – nautiluses, squids, octopuses, cuttlefish, etc. wholly marine; actively mobile predators largest and smartest invertebrates foot modified as tentacles and a siphon nautilus with shell, in others shell is internal (squid, cuttlefish) or lost (octopus) locomotion by jet propulsion: siphon expels water from mantle cavity Cephalopods – nautiluses, squids, octopuses, cuttlefish, etc. capable of learning and memory tasks can learn by observation of others (experiments with octopuses)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The cephalopod eye – single lens eye convergent with that of vertebrates excellent visual acuity some common genes ( rhodopsin , PAX6 ) involved in eye development in the two groups concept of “deep homology” (see recent Nature article*) *Shubin, N. et al. 2009. Deep homology and the origins of evolutionary novelty.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This document was uploaded on 03/18/2012.

Page1 / 8

BIS2C_Lect30_Ward_Annelida_ppt - BIS2C Winter 2012 (Ward)...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online