Annelida (Echiura, Sipuncula, Oligochaeta, Hirudinidia) Flashcards
What are the main features of Echiura (spoon worms)?
Lack of segmentation Exclusively marine Burrowers in cracks or shells Complete digestive system Closed circulatory system Epidermis as a primary gas exchange organ Setae Separate sexes
What are the main features of Sipuncula (peanut worms)
Lack of segmentation and setae Burrowers in cracks or shells Complete digestive system (U-shape) No circulatory system Tentacles as gas exchange organ Separate sexes
Oligochaeta locomotion is the same circular muscular/longitudinal muscle contraction locomotion, but how to Hirundinida (leeches) move?
Looping walk or undulatory swimming
How do male earthworms find females?
Follow a trail of pheromones
Discuss reproduction in earthworms
Sperm funnel - mature sperm is stored until copulation
Testes - hold immature sperm
Seminal vesicles - large white conspicuous organs within which the maturation of sperm occurs
Spermatheca - stores recieved sperm
Ovary - eggs mature in here and move to the coelum before oviduct.
Some species reproduce asexually by parthenogenesis, but most are hermaphrodites and cross-fertilise sexually.
What are the earthworm ecological feeding groups
Endogeic - rich soil feeders, small, horizontal burrows, no pigmentation, topsoil dweller
Epigeic - litter feeder and dweller, pigmented, no burrows, small
Anecic - litter and soil feeder, soil sweller, dorsally pigmented, large, vertical burrows
What is aestivation?
Creating a chamber for summer and ‘aestivating’ - releasing mucus and faeces until winter
What classes of annelid worm belong to clitellata
Hirudinida and oligochaeta
What differences do FRESHWATER oligochaeta have?
Smaller More conspicuous setae More mobile/better developed sense organs Bethnic forms Cutaneous respiration
What are the main characteristics of Hirundinida?
Mainly freshwater and terrestrial Clitellum is only present during breeding season Most have no setae Have suckers Most lack setae Feed on blood/predate Flattened dorsoventrally
What is different about a leeches coelum?
It is packed with muscle and botryoidal tissue. They also have salivary glands full of anticoagulants
Hirundinida can only reproduce sexually. Discuss how
Similar to oligochaetes, although some species have a penis that can inject semen straight into the female
Some species us sperm packages
Fertilization occurs in a cocoon, and juveniles hatch from the cocoon
