Acasta laevigata   Gray,  1825 (Barnacle)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Arthropoda
Class: Maxillopoda
Order:Sessilia
Family:Archaeobalanidae

Description
Color: Shell white

The animal could be detected as nodules with prominent openings where orifice is located. Most have their openings on upper surface some on under surface of host sponge. Shell globular, outer lamina with few minute calcareous points; horizontal growth lines distinct; carinolateral broad reaching basal cup; basal width about 1/2 of lateral compartment; radii and alae oblique. Basis cup-shaped, shallow, bottom pointed, margin crenated with 6 knob-like teeth, a slight ridge from each runs toward pointed area becoming indistinct before reaching it.
Scutum triangular, occludent margin toothed longer than tergal margin; basal margin convex, horizontal growth lines pronounced, densely hirsute; articular ridge prominent; articular furrow deep; adductor ridge distinct; pit for depressor and adductor muscles deep.
Tergum scutal margin straight slightly toothed, apex pointed, spur broad and pointed, fasciole reaching apex of valve; articular ridge short, distinct; articular furrow shallow; crest for depressor muscles faintly indicated.
Mouth parts: Labrum with a deep central notch, frests with 2 or 3 teeth, margins bears fine hairs. Mandible with 4 teeth, inferior angle blunt.
Inner maxilla cutting edge bears 8 to 9 spines, slightly notched below 2 upper large spines, inferior angle rounded with few minute straight setae. Outer maxilla club-shaped, apex produced, inner margin and distal outer margin setose. Palpus small, apex rounded, margin setose.
The numbers of segments of the cirri:
1) Left row:
anterior ramus: 15-1; l0-II; 11-III, 19-IV; 26-V, 23-VI and
posterior ramus: 5-I; 6-II; 10-III, 24-IV; 21-V.
2) Left row:
anterior ramus: 15-I; 9-II; 14-III; 19-IV; 27-V; 29-VI and
posterior ramus: 7-I; 7-II; 11-III; 22-IV; 27-V; 26-VI
3) Left row:
anterior ramus: 14-I; 9-II; 11-III; 16-IV; 23-V; 13-VI and
posterior ramus: 6-I; 7-II; 9-III; 10-IV; 22-V; 24-VI.
Cirri I to III rami unequal, anterior ramus usually longer than posterior ramus, frontal margin setose, setae pinnate. Segments of anterior rami of cirri III to IV have their distal frontal margins armed with spike-like teeth in addition to 3 or 4 pairs of sub-equal setae.
Penis gradually tapering, distinctly annulated, greater part covered with hairs, denser near tip. Basi-dorsal point present and prominent.


Synonym (s)
Acasta laevigata Gray 1825
Acasta laevigata Darwin 1854
Acasta laevigata Gruvel 1903
Acasta laevigata Hiro 1937
Acasta laevigata Nilsson-Cantell 1938a
Acasta laevigata Rosell 1972
Acasta laevigata Hoek 1913

Common Name (s)
Economic Importance and Threats

Ecology

Biogeography


• Andaman and Nicobar Islands, Port Blair INDIA (Record: 2006)
• Andaman and Nicobar Islands, Andaman Islands INDIA (Record: 2006)

Literature Source(s)
  • Fernando, SA (2006) Monograph on Indian Barnacles Ocean science and technology Cell, Kochi 9-199 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org

Page last updated on:2012-05-22

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