PORT PHILLIP BAY


Pycnogonid 

Ascorhynchus longicollis (Haswell, 1885)

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:
longicollis

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

This common species burrows into the seafloor, however it has been observed by divers at night moving on top of the seafloor, presumably feeding. They carry eggs in a protective gelatinous mass wrapped around part of their body. This may prevent the eggs being dislodged as the individual burrows in the sand. The backward-facing proboscis is also possibly an adaptation to decrease resistance when burrowing. Males carry the eggs, holding them between body parts called ovigers that hang under the animal.

Habitat

Sand areas, to depth of 40 m.

Soft substrates

Distribution guide

South-eastern Australia, including western and central Victoria.

Species Group

Sea spiders

Depth

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

Water Column

On or near sea floor

Max Size

2 cm

Commercial Species

No

Global Dispersal

Native to Australia

Species Code

MoV 1350

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 longicollis, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/6250

Text: creative commons cc by licence