BIOL 1030 Lecture 8: Introduction To Invertebrates

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 1030
• Professor: Steven Whyard, Steven Harris

Document Summary

33. 1 >> sponges are basal animals that lack true tissues. Animals in the phylum porifera are known informally as sponges. They are sedentary and live in marine waters or fresh water. Sponges are suspension feeders, capturing food particles suspended in water passing through their body. Water is drawn through pores into a cavity called the spongocoel and out through an opening called the osculum. Choanocytes, agellated collar cells, generate a water current through sponge and ingest suspended food. Sponges consist of a gelatinous noncellular mesohyl layer between two cell layers. Amoebocytes are found in the mesohyl and play roles in digestion and structure. Most sponges hermaphrodites (individuals function as both male and female) 1) fertilization occurs in mesohyl: zygotes develop into agellated swimming larvae that disperse from parent sponge. 33. 2 >> cnidarians are an ancient phylum of eumetazoans. All animals except sponges and a few other groups belong to clade eumetazoa, animals with true tissues.