Sacculina scabra Boschma, 1931

Chan, Benny K. K., 2004, First Record Of The Parasitic Barnacle Sacculina Scabra Boschma, 1931 (Crustacea: Cirripedia: Rhizocephala) Infecting The Shallow Water Swimming Crab Charybdis Truncata, Raffles Bulletin of Zoology 52 (2), pp. 449-453 : 451

Sacculina scabra Boschma, 1931

Diagnosis. – The externa is orange-yellow and globular in shape ( Fig. 1 ). The external cuticle of the externa is smooth without excrescences. The paired male receptacles are globular, located close to each other and at the posterior region of the visceral mass ( Fig. 2A, B ). The linings of the receptacle ducts are thick and folded ( Fig. 2C ). The two receptacle ducts are united for part of their lengths ( Fig. 2D ) but separated again near the duct openings ( Fig. 2E ). The internal linings of the receptacle ducts are cuticularized at their openings under light microscopes ( Fig. 2F ; the entire internal linings of Sacculina spp. can be covered with a very thin layer of cuticles which can only be observed under Transverse Electron Microscopes; Høeg, 1987). The number of colleteric gland tubules in sections is 50 – 55 and they are arranged in five rows. The size of the tubules ranges from 180 to 250

gm ( Fig. 3 ).

Figures

Fig. 1. Drawing of the externa of Sacculina scabra from a male and female Charybdis truncata. Scale bar in mm.

Fig. 2. Transverse sections of A) male receptacles, B) receptacle duct near the male receptacles showing the thick lining, C) folded lining (f) of receptacle duct, D) the paired receptacle ducts joined in the same chamber, E) the receptacle duct separated again at the region of the duct opening, F) receptacle duct opening, showing thick, cuticular lining. All the figures are to the same scale. Scale bar in m.

Fig. 3. Colleteric gland tubules of Sacculina scabra on the A) left hand side and B) right hand side of the visceral mass. Scale bar in m.