PORT PHILLIP BAY


Pycnogonid 

Ascorhynchus compactus Clark, 1963

View scientific description and taxonomy

Scientific Details

Family level characters.
TRUNK: Elongate, with or without strong ridges or projections.
PROBOSCIS: Large, pyriform. Usually carried ventrally and directed to posterior.
SCAPE: 1-2 segmented.
CHELA: Tiny, usually atrophied in adults.
PALPS: 9-10- segmented. Two proximal segments very short.
OVIGERS: 10-segmented in both sexes larger in male; terminal claw present. Numerous compound spines on segments 7-10; no apophysis.
LEGS: Eight legs, long slender.
TARSUS: often longer than propodus.
AUXILIARY CLAWS: absent.
CEMENT GLANDS: Open through dorsal pores or tube or lateral pores on femur and first tibia.

Genus level characters.
TRUNK: Elongate, with or without strong ridges or projections.
ABDOMEN: long, segmented at base, usually angled downwards and reaching beyond coxa 1 of fourth legs,
PROBOSCIS: Large, pyriform. Usually carried ventrally and directed towards posterior.
SCAPE: 1-2 segmented.
CHELA: Tiny, usually atrophied in adults.
PALPS: 9-10- segmented. Two proximal segments very short.
OVIGERS: 10-segmented in both sexes larger in male; terminal claw present. Numerous compound spines on segments 7-10; no apophysis.
LEGS: Long slender, smooth or variously setos.

Taxonomy

Phylum:
Arthropoda
Subphylum:
Cheliceriformes
Class:
Pycnogonida
Order:
Pantopoda
Family:
Ammotheidae
Genus:
Ascorhynchus
Species:
compactus

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 or more eyes. Eight segmented walking legs attached to the sides of the trunk. Long abdomen behind trunk, segmented at base, usually angled downwards. Leg span about 2 cm.

Biology

The male carries eggs in a sausage-like mass wrapped around part of the body. The scientific name of this species refers to the compact size of the body. Males carry the eggs, holding them between body parts called ovigers that hang under the animal.

Habitat

Intertidal areas, usually under rocks.

Reefs

Coastal shores

Distribution guide

South-eastern Australia, including western and central Victoria.

Species Group

Sea spiders

Depth

Shore (0-1 m)
Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

2 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, Ascorhynchus compactus, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 23 Jul 2017, http://portphillipmarinelife.net.au:8098/species/6249

Text: creative commons cc by licence