Oceanography: Structures of a Squid

Squid Anatomy and Function

• Mantle:

  • Serves as a protective cavity for internal organs.
  • Maintains nutrients needed for survival.
  • Colossal squid's mantle measures approximately 2.5 meters long and 982 millimeters wide, similar in diameter to a truck tire.

• Fins:

  • Paired tail fins are muscular and located on the upper mantle surface.
  • Primarily used for propulsion and changing direction.
  • Colossal squid fins measure 1,183 millimeters long and 982 millimeters wide, enabling rapid movements when attacking prey.

• Siphon:

  • Also known as the funnel, situated on the ventral surface of the mantle.
  • Functions include respiration, waste discharge, and locomotion.
  • Works by sucking in water for respiration through the mantle opening and expelling it for jet propulsion.

• Beak:

  • The squid's mouth, resembling a parrot's beak.
  • Lower beak overlaps the upper beak, made of chitin and surrounded by muscle.
  • Used to chop and slice prey; food is further processed by the radula before entering the stomach.

• Nephridia:

  • Paired organs with functionality akin to vertebrate kidneys.
  • Responsible for excretion of metabolic wastes.
  • Various types exist, including metanephridia and protonephridia.

• Liver:

  • Large, elongated gland that aids in digestion by releasing secretions into the stomach.
  • Supports enzymatic processes necessary for food breakdown.

• Ctenidium (Gill):

  • Paired, feathery organs essential for respiration.
  • Increases the surface area for gas exchange in water.