Phyla Annelida And Mollusca Flashcards
Xtics of phylum Annelida
Tribloblasts
Bilateral symmetry
Varying cephalization degrees
PERIVISCERAL ceolom present
Closed blood system
Chitinous chaetae in segments
What is the larval form of Annelida and Mollusca?
Trochophore larvae
What is the excretory organ of Annelida?
Segmented, ciliated NEPHRIDIA
Classes under Annelida
Oligochaeta- Earthworms
Polychaetae
Hirudinea - Leeches
Class Polychaeta Xtics
Commonly called marine bristle worms
NUMEROUS CHITINOUS CHAETAE
Dioecious
No suckers
Free-swimming trachopore larvae
External fertilization
Parapodia
Lateral extensión of podia(feet)
Xtics of Class Oligochaetae
Earthworms
No distinct cephal(head) + suckers
FEWER CHAETAE than polychaetae
No parapodia + chaetae occur singly
Hermaphrodites
Reproduction by copulation + cross fertilization
Class Hirudinea Xtics
Highly specialized Annelids
Leeches
All members have 33/34 segments
No suckers, parapodia, suckers, head, chaetae
Ectoparasites
Hermaphrodites
Reproduce by Cross fertilization
Xtics of phylum Mollusca
Soft bodied
Bilateral symmetry
Body divided into head, ventral muscular foot and dorsal visceral lump
Blood system consists of heart, arterial and venous systems which extend into an extensive HAEMOCOEL
HAEMOCYANIN is respiratory pigment
Oviparous
Zygote starts as trochophore larvae and later transforms into a VELIGER larvae
What are the first and final stages of zygotes in Mollusca and Annelida?
Trochophore larvae- first
Veliger larvae- last
The seven classes under Mollusca
Aplacophora
Monoplacophora
Polyplacophora
Scaphopoda
Gastropoda
Bivalvia
Cephalopoda
Xtics of class Aplacophora
Means “no plates”
Lack foot, mantle, shell
Spicules in place of shells
