CLASSIFICATION OF BALANUS OR ACORN BARNACLE

PHYLUM :- ARTHROPODA (Jointed appendages.)

CLASS :- CRUSTACEA (Thick exoskeleton, antennae 2 pairs)

SUB-CLASS :- CIRRIPEDIA (Sessile adults without compound eyes and antennae, with carapace and mandibular palps and with 6 pairs of biramous thoracic limbs)

ORDER :- THORACICA (Non-parasitic, carapace of calcareous plates and 6 pairs of thoracic appendages.)

GENUS :- Balanus

GEOGRAPHICAL DISTRIBUTION

  • It has cosmopolitan distribution but especially found along Pacific coast, North Atlantic coast, West Indies and Washington to Alaska.

HABIT AND HABITAT

  • Balanus is attached to rocks and molluscan shells in great numbers between tide-marks in shallow water. It may attach to any floating object also.

BALANUS OR ACORN BARNACLE

GENERAL CHARACTERSTICS OF BALANUS OR ACORN BARNACLE

  • Commonly called as Rock barnacle or Acorn barnacle.
  • Stalk is absent to the shell covering the animal is directly attached to the substratum or rocks.
  • Head is short and broad. 
  • Mantle surrounding the body is covered by six calcareous plates, consisting of unpaired carina, rostrum and 2 pairs of carino-lateral plates. Edges of the plates overlap and fit together forming cylinder. Outer surface of each plate shows 3 divisions, a central portion and two wings.
  • Opening of the shell is provided with a movable fourfold lid or operculum, composed of 2 scuta and 2 terga.
  • In water the barnacle protrudes through the opening six pairs delicate, curled, fringed and jointed thoracic legs to collect food.
  • Life cycle includes nauplius larva.
BALANUS OR ACORN BARNACLE

SPECIAL FEATURES

  • Balanus titinnabulum has food value in some countries. Barnacles are highly modified crustaceans in which hermaphroditism is common. Male and female live in permanent association.

IDENTIFICATION

  • The animal contains carina, scuta, terga and protruding thoracic appendages and all above features, hence it is Balanus.

BALANUS OR ACORN BARNACLE
BALANUS OR ACORN BARNACLE
OUR POSTS

Leave a Comment

Your email address will not be published. Required fields are marked *