PORT PHILLIP BAY


Pycnogonid 

Ammothea ovatoides Stock, 1973

View scientific description and taxonomy

Scientific Details

Family level characters.
TRUNK: Variably fused or articulated. Often compact and almost circular in outline.
SCAPE: 1or 2-segmented or absent.
CHELA: fingers generally reduced in adults but maybe chelate, atrophied or absent.
PALPS: 1-10 segments, usually 8-9 segments. Present in both sexes.
OVIGERS: 3-10 segments, both sexes but larger in males. No terminal claw. In some genera the number of oviger segments is fewer in the female. No apophysis. Terminal spines are compound.
LEGS: Eight only. Propodal heel usually well developed. Auxiliary claws present or absent. Dorsodistal femoral cement glands present.

Genus level characters.
TRUNK: Dorsal posterior ridges on first 3 trunk segments, with or without tubercles. Lateral processes separated.
PROBOSCIS: Usually inflated
SCAPES: 0-1-2 segmented.
CHELAE: Either present (presumably functional), atrophied in adults, or completely absent.
PALPS: 6- 9 segments.
OVIGERS: 9 or 10-segments both sexes, (only one species with 9 segments), no apophysis on segment five; distal three segments carries anaxially on seventh segment, spines few, simple or denticulate, no terminal claw.
LEGS: Anterior and posterior propodi often differ in size between pairs of legs.
TARSUS: Shorter than propodus.
AUXILIARY CLAWS: Large.
CEMENT GLANDS: Usually a single dorsodistal pore on femur.
GENITAL PORES: Male on low mound, ventral surface legs 3 & 4; female ventral surface coxa 2 all legs.

Taxonomy

Phylum:
Arthropoda
Subphylum:
Cheliceriformes
Class:
Pycnogonida
Order:
Pantopoda
Family:
Ammotheidae
Genus:
Ammothea
Species:
ovatoides

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. Small abdomen behind trunk. Leg span about 1 cm.

Biology

The scientific name of this species refers to the resemblance of the serrated mouth parts (palp) found in a related species. Associations with other species, such as hydroids or seaweeds, are yet to be determined. Males carry the eggs, holding them between body parts called ovigers that hang under the animal.

Habitat

Recorded from seaweed, bryozoans and hydroids.

Reefs

Distribution guide

South-eastern Australia, including central and eastern Victoria.

Species Group

Sea spiders

Depth

Shallow (1-30 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, Ammothea ovatoides, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 25 Feb 2025, http://136.154.202.208:8098/species/6246

Text: creative commons cc by licence