PORT PHILLIP BAY


Pycnogonid 

Pseudopallene pachycheira (Haswell, 1885)

View scientific description and taxonomy

Scientific Details

Family level characters.
TRUNK: Elongate with widely spaced lateral processes or compact with lateral processes touching.
ABDOMEN: Typically short, inflated.
EYES: 4-8.
PROBOSCIS: Variable but usually short.
SCAPES: 1 or 2-segmented.
CHELAE: Full functional and often robust.
PALPS: Typically lacking but maybe present with 1 to 4 segments, often sexually dimorphic.
OVIGERS: Typically 10-segmented, rarely 9 segmented, with apophysis on 5th segment, strigilis, terminal claw present or absent.
LEGS: Eight legs only, long or short.
TARSUS: shorter than propodus.
AUXILIARY CLAWS: Present or absent.
CEMENT GLAND(S): If present, on ventral femora but seldom evident.
GENITAL PORES: second coxae of all legs of female, either legs 3 & 4 or all legs of male .

Genus level characters.
TRUNK: smooth, segmented, neck broad, anterior region of cephalon swollen. Lateral processes narrowly separated.
ABDOMEN: short, rounded distally.
EYES: 4, usually pigmented. Ocular tubercle squat, rounded.
PROBOSCIS: with fringe and mamilliform tip.
SCAPES: 1-segmented, directed ventrally in southern Australian material.

Taxonomy

Phylum:
Arthropoda
Subphylum:
Cheliceriformes
Class:
Pycnogonida
Order:
Pantopoda
Family:
Callipallenidae
Genus:
Pseudopallene
Species:
pachycheira

Other Names

  • Sea spider

General Description

Body with proboscis projecting outward from front, with the mouth at the tip. Central body (trunk) behind the proboscis, with a raised, rounded area (tubercle) bearing four eyes. Eight segmented walking legs attached to the sides of the trunk. Short abdomen behind trunk, rounded at tip. Leg span about 1 cm.

Biology

This rarely collected sea spider is virtually invisible in the wild unless it moves. It hides by using its colour and annulated legs to perfectly camouflage against the bryozoans on which it lives. Males carry the eggs, holding them between body parts called ovigers that hang under the animal.

Habitat

Usually on soft bryozoans, possibly seagrass areas, to depth of 160 m.

Reefs

Seagrass meadows

Distribution guide

South-eastern Australia, including central Victoria.

Species Group

Sea spiders

Depth

Shallow (1-30 m)
Deep ( > 30 m)

Water Column

On or near sea floor

Max Size

1 cm

Commercial Species

No

Global Dispersal

Native to Australia

Conservation Status

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

Author

article author Staples, D.

David Staples is a consultant with expertise in pycnogonid taxonomy.

citation

Cite this page as:
Staples, D., 2011, Pycnogonid, Pseudopallene pachycheira, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 19 Oct 2017, http://portphillipmarinelife.net.au:8098/species/6267

Text: creative commons cc by licence