Stigmatopora narinosa

Stigmatopora spp. do not have a caudal (tail) fin, and brood on the tail. They share this characteristic with the seahorses (Hippocampus spp.), the Weedy Seadragon (Phyllopteryx) and Leafy Seadragon (Phycodurus), and the Solegnathus spp. pipefish. The tail of Stigmatopora spp. tapers to a fine point and is prehensile.

The Stigmatopora currently comprises the Southern Gulf pipefish (accepted/in press), the Wide-body Pipefish S. nigra, Spotted pipefish S. argus, and the New Zealand Smooth Pipefish S. macropterygia. The Southern Gulf pipefish is most similar in meristics to S. nigra in also having the dorsal fin initiating on about the 5 to 7^th trunk ring and the lateral trunk ridge terminating on or about the first tail ring. In other Stigmatopora species the dorsal fin originates on the 9 to 13^th trunk ring. The Southern Gulf pipefish is distinguished from the Wide-body pipefish in having nine, rather than six sub-dorsal tail rings, no distinct lateral trunk ridge, a broad and elevated snout, and distinct coloration.

Another unrelated pipefish of similar shape and colour with a deep snout is the Knife-snout pipefish Hypselognathus rostratus. Most of the dorsal fin of the Knife-snout Pipefish is over the tail.

The Southern Gulf Pipefish; the dorsal fin starts at 6 rings from the head and extends past the vent for 9 tail rings.

The above image of a Southern Gulf pipefish shows the rings and the position of the dorsal fin. Image R Browne. You can see clearly that the dorsal fin starts at the 6th body segment suggesting a congener of S. nigra, and told apart from S nigra by having nine subdorsal tail rings.

The Wide-body pipefish Stigmatopora nigra - greyscale image - is the species superficially most similar to the Southern Gulf pipefish. This species can easily be distinguished from the Southern Gulf pipefish in the field by the having only about 6 sub-dorsal tail rings in contrast to 9 in the Southern Gulf pipefish, the shape of the head and snout a generally green colour, and no red/brown rings on the trunk and tail.

This species is also characterized by moderate length broad-high snout, and red/brown rings on the ventral surface.

The image to the right shows the holotype Southern Gulf pipefish male collected by Kevin Smith. Also note the elevated ridge at the end of the snout (image Kevin Smith).

Stigmatopora narinosus

Above - The Southern Gulf pipefish is attached by its red prehensile tail to seaweed. The pattern on this specimen is fairly typical of the species. However, the pattern and colour can vary.

The image on the left /above of the underside of a Southern Gulf pipefish shows the broad snout.

The image on the right/above shows a preserved specimen of the Southern Gulf pipefish. In life the eye protrudes beyond the orbit.

DISTRIBUTION: The right map shows the locations in South Australia where vouched confirmed specimens of the Southern Gulf pipefish have been found. The map also shows the Interim Marine and Coastal Regionalisation of Australia (Australian Dept. of Environment and Heritage) for South Australia.

DISTRIBUTION: The Southern Gulf pipefish appears to be limited to a few scattered inshore sites. There has been extensive trawling and hand netting of sea grass areas in shallow to moderate depths in both Spencer's and Gulf St. Vincent. Although many hundreds of other pipefish, particularly other Stigmatopora sp. (Wide-body pipefish and Spotted pipefish), have been sampled by inshore trawls the Southern Gulf pipefish has been rarely been captured. Considering the moderate abundance of the Southern Gulf pipefish in many known sites this lack of capture shows the Southern Gulf pipefish is probably found only close inshore.

MICRO-HABITAT: The Southern Gulf pipefish has been found in areas with brown algae and rubble/rock substrate within sea grass, as well as in small patches of sea grass with sandy substrate within brown algae. The Southern Gulf pipefish therefore appears to inhabit the transition zone between Posidonia sea grass and brown algae on rubble/sand. If this is the case the Southern Gulf pipefish inhabits only a small area of micro-habitat within its restricted range.

Left: The head and body of the Southern Gulf pipefish is perfectly camouflaged with the encrusted Posidonia. The shape of the snout enables this pipefish to feed on its prey. The snout acts as a bellows capturing passing prey such as Mysids.

Left. The yellow > points toward the eye of a well hidden Southern Gulf pipefish in both a wide and closer-up image the pipefish shelters in sea grass. The coarse sandy broken bottom preferred by this species is in evidence (image Kevin Smith).

POPULATION ECOLOGY: Little known. ABOVE: Zostera and Posidonia sea grass beds (as shown) with juveniles and breeding adults have been found in 1.5 to 2.0 meters in depth. Also see REPRODUCTION.

REPRODUCTION: The few (eleven) specimens of the Southern Gulf pipefish in museum collections to 2003 of 60 mm to 80 mm length did not include mature brooding males. Recently a brooding male found by Kevin Smith was 154 mm in total length. This is much longer than the minimum brooding length of 53 mm of its congener the Wide-body pipefish. The male Southern Gulf pipefish had a unique brood pouch structure and almost triple the number of eggs 98 than any other Stigmatopora sp. In South Australia the Wide-body Pipefish lays a maximum of 24 eggs and the Spotted pipefish a maximum of 38 eggs. The hatching larvae of the Southern Gulf Pipefish were 18 mm long in contrast to those of the Wide-body pipefish of 13 mm and the Spotted Pipefish of 28 mm.

29/12/04 Kevin Smith observed many juvenile Southern Gulf pipefish 60 to 80 mm inshore at southern Yorke Peninsular in Gulf St Vincent.

In contrast to the other Stigmatopora spp. the holotype male Southern Gulf Pipefish had three staggered rows of cups for the eggs containing 64 cups with a second elevated layer of eggs along in the brood pouch. Separating the second layer of eggs was a reproductive structure. It is a membrane with two rows of egg pouches that was positioned between the body layer of eggs and the second layer of eggs.

CAMOUFLAGE: There is a Southern Gulf pipefish horizontally in the left hand image above, and vertically near the top of the right hand image. They are a cryptic species and well camouflaged. A note from Kevin Smith 9/02/03 referring to the above image. There is a Southern Gulf pipefish in each: "3 to 4 meters depth. The other divers I was with knew of the location of these fish and Short-headed Seahorse 10-30 m offshore". It appears that this species has been seen by divers for some years without its significance being realised".

CONSERVATION: The Southern Gulf pipefish is endemic to South Australia, and appears to have the most restricted range and micro-habitat of any pipefish species in Southern Australasia. Its inshore habitat and distribution in areas subject to development make this species conservation dependent. Preservation and monitoring of the known locations of the Southern Gulf pipefish should enable the conservation of this species. Longer term conservation could be threatened by climate change and depends on increased knowledge of the Southern Gulf pipefish range, distribution, habitat, population ecology and reproduction.