PORT PHILLIP BAY


Pycnogonid 

Nymphon molleri Clark, 1963

View scientific description and taxonomy

Scientific Details

Family level characters.
TRUNK: Elongate, typically with lateral processes well separated.
ABDOMEN: short, unsegmented at base.
EYES: 4
PROBOSCIS: short
SCAPES: One segmented.
CHELAE: Usually large, well developed, with teeth.
PALPS: 5-segmented (one genus has 4 segments).
OVIGERS: 10-segmented both sexes, compound spines and full strigilis, terminal claw present. No apophysis
LEGS: 8, 10 or 12 legs.
TARSUS: Shorter than propodus.
AUXILIARY CLAWS: Present or absent.
CEMENT GLAND: Ventral, rarely evident.
GENITAL PORES: Male, ventral surface coxa 2 legs 3 & 4; female all legs.

Genus level characters.
TRUNK: Usually elongate, segmented. Lateral processes well separated or crowded, setae, spines, glabrous and rarely with tubercles.
ABDOMEN: unsegmented.
EYES: Ocular tubercle at rear of cephalic segment.
PROBOSCIS: Short
SCAPES: One-segmented.

Taxonomy

Phylum:
Arthropoda
Subphylum:
Cheliceriformes
Class:
Pycnogonida
Order:
Pantopoda
Family:
Nymphonidae
Genus:
Nymphon
Species:
molleri

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, unsegmented. Leg span about 4 cm.

Biology

These well-camouflaged sea spiders are typically found on top of sponges with their legs spread apart. They have crimson red egg masses, but other colours may occur like they do in other species. They feed on small polychaete worms. This species is named after the collector of many Australian pycnogonids, Captain K. Moller. Males carry the eggs, holding them between body parts called ovigers that hang under the animal.

Habitat

Usually on sponges, also associated with hydroids, bryozoans and seaweed, to depth of 29 m.

Reefs

Distribution guide

South-eastern Australia, including central Victoria.

Species Group

Sea spiders

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

4 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, Nymphon molleri, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 18 Dec 2017, http://portphillipmarinelife.net.au:8098/species/6254

Text: creative commons cc by licence