Annelids

• What is the scientific name for the segmented worms?

  Annelida
• What is the expected outcome of the session on Annelida?

  To describe characteristics and features of Annelida
• What are the four groups of convenience for worms?

  Bilaterally symmetrical, soft-bodied, veriform shape
• Which phylum includes segmented worms?

  Annelida
• What notable evolutionary change involves the development of a head and sensory organs?

  Cephalisation
• What does metameric segmentation refer to?

  Design by module in body structure
• What type of body cavity do Annelids possess?

  A true coelom
• What are the three sections of an Annelid's body?

  Prostomium, trunk, pygidium
• What is the typical reproductive strategy of Annelids?

  Normally sexual and gonochoristic or hermaphroditic
• What is the classification of Annelida within the animal kingdom?

  Animalia, Eumetazoa
• What does the term 'Annelida' mean in Latin?

  Ringed or segmented worms
• What is the main feature of the Polychaeta class?

  Presence of chaetae (setae)
• What is the purpose of species identification keys in Annelida?

  To identify species based on morphological features
• What is the feeding strategy of Polychaetes that involves mucous production?

  Mucous net
• How do Polychaetes typically move?

  Swimming and crawling
• What is the term for the reproductive strategy involving epitoky in Polychaetes?

  Swarming
• What is the significance of worm farming in the context of Annelids?

  It is a big business for bait
• What was the estimated number of ornamental polychaetes sold annually in the UK?

  Up to 18,500 ornamental polychaetes
• What are the wider effects of bait digging on Annelids?

  Impacts on undug and dug populations
• What are the general characteristics of Annelida?

  • Bilaterally symmetrical and vermiform
  • More than two cell layers, tissues, and organs
  • True coelom, often divided by internal septa
  • Through gut with mouth and anus
  • Three sections: prostomium, trunk, pygidium
  • Nervous system with anterior nerve ring and ventral nerve chord
  • True closed circulatory system
  • No true respiratory organs
  • Reproduction is normally sexual and gonochoristic or hermaphroditic
• What are the major groups within the Annelida?

  1. Polychaeta (bristle worms)
  2. Clitellata (earthworms and leeches)
  3. Errantia (free-moving)
  4. Sedentaria (burrow or tube dwelling)
• What are the reproductive strategies of Polychaetes?

  • Asexual reproduction
  • Sexual reproduction
  • Epitoky and swarming
• What are the impacts of human exploitation on Annelid groups?

  • Worm farming for bait
  • Aquarium trade
  • Unregulated worm digging
  • Effects on populations and ecosystems
• What is the classification of Annelida within the animal kingdom?

  Animalia, Eumetazoa
• What notable evolutionary changes are associated with Annelida?

  Cephalisation and metameric segmentation
• How do chaetae contribute to Polychaete locomotion and feeding?

  They aid in movement and food capture
• What is the role of parapodia in Polychaete morphology?

  They assist in locomotion and respiration
• What ecological roles do Annelids play in their environments?

  They contribute to soil aeration and nutrient cycling
• What methods are used to study Annelid species in the field?

  Species identification keys and field surveys
• What is the phylum of segmented worms?

  Annelida
• Which classes are included in the phylum Annelida?

  Aeolosomata and Clitellata
• What is the significance of the clitellum in Clitellata?

  It has ventral glands for reproduction
• How many species are estimated in the phylum Annelida?

  Approximately 75,000 species
• What is the typical size of organisms in the class Aeolosomata?

  Mostly minute, less than 1 cm
• How do Aeolosomata reproduce?

  They reproduce asexually by paratomy
• What type of reproduction do hermaphrodites in Aeolosoma likely engage in?

  Pseudocopulation for sperm transfer
• What is the primary habitat of Aeolosoma species?

  Freshwater and marine interstitial spaces
• What is the relationship of Aeolosomata to other annelid groups?

  Its relationship is not clearly defined
• What are the subclasses under the class Clitellata?

  Oligochaeta and Hirudinea
• What distinguishes Megadriles from microdriles?

  Megadriles are giant earthworms