Platylepas decorata   Darwin,  1854 (Barnacle)
Organism information awaits expert curation
Class: Maxillopoda

Max size: Carinorostral diameter 6 mm; lateral diameter 4.5 mm; height 1 mm.

Color: Parietes, radii and alae white, sheath brownish white, shell covered by a yellowish membrane near base.

Greatly depressed, oval or circular, with the compartments convex, basis slightly lesser in convexity than the shell.
Walls thick, solid; compartments weakly united, rostrum much broader than carinolateral and carinolateral of equal width; each compartment divided by a median radial inward fold from summit to middle and by a ride from middle to base. On either side of the median line the parietes are externally sculptured by four double ridges alternating with three simple ridges. A double ridge is divided into two smaller ridges by a narrow longitudinal depression; each small ridge is anteriorly narrow; extends from base to middle of shell, and ornamented with large and small beads arranged transversely. A simple ridge is equal in width extending from base to lower margin of sheath, and uniformly ornamented with small beads arranged transversely. All ridges including central one extend beyond basal margin as teeth, single ridged tooth than double ridged tooth. Inner surface of each compartment with prominent central midrib and three prominent ridges on either side corresponding to simple ridges on external surface. Midrib projects inwards to a distance equalling half the breadth of the compartment with the basal edge smooth. Sheath, thin near orifice, thick at base and descends to middle of shell. Radii narrow with crenulated edges, alae with sutural edges smooth. Basis membranous. Opercular valves narrow and elongated. Opercular membrane thick, without spines. Scutum flat, plain oblong, twice as long as broad; rostral end rounded and narrow. Tergum flat, delicately ridged on external surface equalling scutum in length, carinal end more pointed than the scutal end.
Mouth parts-Labrum with six large straight teeth and three narrow curved teeth on either side of deep central notch; palp parallel sided, with obliquely rounded distal ends, covered with long pectinated hairs.
Maxilla with the free edge bearing a notch below upper large pair of spines; free edge below notch inwardly curved, bearing two upwardly directed spines; four spines on the straight edge of maxilla above the two narrow lower spines. Upper, lower margins and surface fringed with a number of long hairs. Outer maxilla oval, with long non-pectinated hairs, on the outer margin and distally; lower lobe with long hairs on margin.
Mandible with five teeth, first tooth deeply marked off from the rest; second to fifth teeth double - pointed small pointed cuspid teeth between second and third and third and fourth teeth; lower angle with three long spines. Upper, lower margins and surface fringed with number of long hairs.
Cirri: Cirrus with unequal rami; anterior ramus half as long again as posterior; both rami with protuberant margins and pectinated setae. Cirri II and III with equal rami. Terminal segments of rami with pectinated setae; other segments with non-pectinated setae. Cirri IV - VI with equal rami. Each segment of cirri IV - VI with a pair each of very long, curved, pectinated setae, moderately long, straight, pectinated setae, and two pairs of short non-pectinated setae; at the posterior distal angle, each segment bears a pair of setae.
The number of segments in the rami in two individuals are given below:
Right side: Anterior ramus, Posterior ramus:
I Cirri - 10,8; II Cirri - 8,8; III Cirri - 9,7; IV Cirri 15,15; V Cirri - 16, 16; VI Cirri - 19, 19. 2. Right side: Anterior ramus, Posterior ramus : I Cirri -9,6; II Cirri -8,8; III Cirri -9,9; IV Cirri -15,16; V Cirri-17, 17; VI Cirri -21, 20.
Penis long, annulated with few scattered hairs along its length rather more at the end.

Synonym (s)
Platylepas multidecorata Daniel 1962b
Platylepas decorata Darwin 1854
Platylepas decorata Monroe and Limpus 1979

Common Name (s)
Economic Importance and Threats

Habitat:  Demersal


• Andaman and Nicobar Islands, Little Andaman INDIA (Record: 1961)

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 -
  • Sealifebase Available at -

Page last updated on:2012-05-21

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