PORT PHILLIP BAY


Hydroid 

Pycnotheca producta (Bale, 1882)

View scientific description and taxonomy

Scientific Details

Family level detail.
Colony creeping (stolonal), branched or unbranched, hydrocladia alternate, hydrothecae only on hydrocladia (branches), small, without lateral nematothecae, gonophores with eggs, gonothecae large.

Genus level detail.
Small plumose hydroids. Colony monosiphonic, hydrocladia alternate, hydrotheca cup-shaped with internal septum, margin circular, one median superior and one median inferior nematotheca, no lateral nematothecae

Species identification.
Colonies spreading over a seagrass leaf from a creeping hydrorhiza, stems well spaced apart, monosiphonic, hydrocladia alternate on stem, one on each stem internode. Hydrotheca occupying most of hydrocladial internode, scoop-shaped, a wedge of perisarc passing downward into hydrotheca from upper wall, a vestigial median nematotheca on a prominence of the internode behind the hydrotheca and a small median pore below margin of the hydrotheca. Female gonophohore with many small eggs in a gonotheca borne on hydrorhiza, large, irregularly ovoid, recumbent to substrate, surface rugose. Colour: white, often with a faintly bluish tinge when seen in the water. Up to 2 cm high.

Taxonomy

Phylum:
Cnidaria
Class:
Hydrozoa
Subclass:
Leptothecatae
Order:
Conica
Family:
Kirchenpaueriidae
Genus:
Pycnotheca
Species:
producta

General Description

Colony of individual polyps (hydranths) joined by root-like network of tubular stolons at the base. Colony shape is feather-like (pinnate). Colour: white, often with a faintly bluish tinge when seen in the water. Up to 2 cm high.

Biology

Colonies of this species become fertile in late spring to summer.

Habitat

On leaves of seagrasses in shallow waters.

Seagrass meadows

Distribution guide

Southern Australia.

Species Group

Hydroids

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

2 cm

Diet

Plankton or Particles

Harmful

Generally not harmful but still able to sting bare skin.

Commercial Species

No

Identify

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Not listed
  • IUCN Red List : Not listed

Author

article author Watson, J.

Jan Watson is a consultant with expertise in hydroid taxonomy.

citation

Cite this page as:
Watson, J., 2011, Hydroid, Pycnotheca producta, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 27 Jun 2017, http://portphillipmarinelife.net.au:8098/species/7114

Text: creative commons cc by licence