Forskalia tholoides   Haeckel,  1888 (Hydrozoan)
Organism information awaits expert curation
Class: Hydrozoa

Size: Upto 40-60 cm.

Nectosome: Very large, campanulate, multiserial with diameter of 30-40 mm. With 16-20 longitudinal rows on twisted stem (laeotropic spiral) in medium sized colony. With 300-400 nectophores in longer colony.

Pneumatophore: Small ovate, with 8 vertical septa, pink in color at apex. With basal pore.

Nectophore: Prismatic, polygonal lateral facets. Attached to stem by long, triangular pedicel-twice as long as breadth of nectophore. With long pedicular canal without rete, joining nectosac at top, dividing into four simple straight radial canals before joining circular canal.

Siphosome: 3-4 times longer than nectosome, bearing 40-50 cormidia on spirally twisted stem (dexiotropic spiral- opposite to twisting of nectosome).

Gastrozooids: 10-15 mm long, borne on long peduncles 15-20 mm in length, covered with series of small bracts. With 16 red longitudinal liver ridges - 4 long per radial 4 shorter inter-radial and 8 small adradial between former and latter.

Tentacles: Long, strong, bearing tentilla; tentilla non involucrate, unicornuate; cnidoband with 4 spiral coils, large nematocysts on lateral sides, and minute ones on terminal filament.

Gonodendra: Arise from bases of gonopalpons. Stalks long, bearing clusters of gonophores, female at proximal stalk and male at distal part. Female gonophore smaller, pyriform or subspherical, monovon, with network of spadicine canals. Male gonophore ovate or club-shaped with central spadix. Both umbrella with 4 radial canals connected by a small ring canal at velum.

Bract: Siphosome covered with innumerable bracts (1000), mostly small, leaf-like without crest or denticles. Larger protective ones on outside of siphosome. Larger bracts three sided, prismatic asymmetrical, dorsal surface denticulated.

Synonym (s)
Forskalia tholoides Haeckel, 1888
Forskalia tholoides Totton, 1965

Common Name (s)
Economic Importance and Threats

Habitat:  Pelagic


• Off South East Coast INDIA (Record: 1962-1965)

Literature Source(s)
  • Daniel, R (1985) Fauna of India and the adjacent countries (Coelenterata: Hydrozoa: Siphonophora) ZSI 440 pp Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2010-06-18

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