Sydney’s Pygmy Pipehorse, Idiotropiscis lumnitzeri Kuiter 2004

Endemic to New South Wales, from Cabbage Tree Bay, Manly, to at least Bawley Point, New South Wales.

Inhabits semi-exposed rocky reefs covered in clumps of red algae or bryozoans at depths to 30 m. Individuals appear to be site-attached, remaining on the same small reef areas for much of the year.

Dorsal fin 15–16; Pectoral fin 13.Trunk rings 11; tail rings 43–44.

Head large, length 86–91% of trunk length and angled ventrally approximately 25° from longitudinal axis of body; snout short, length 2.2–2.6 in head length; snout depth 46% (45–47%) of its length; top of head with prominent, tall, frontal ridge originating well behind eye, with thick, long, branched, fleshy dermal appendage, reaching forward to above tip of snout; trunk length 18–20% TL; numerous simple to fern-like branched, fleshy dermal appendages on head and body, well-developed above eye, under snout and at various intersections of rings and superior ridges on trunk and tail; trunk very deep, its greatest depth 73% of its length; superior trunk-ridge ending below dorsal-fin base, above origin of superior tail-ridge; tail prehensile.

Dorsal-fin base arched upwards at centre.

To 5.5 cm TL

Overall whitish to reddish or dark grey, with brown to reddish blotches or irregular banding; sometimes uniformly burgundy-red. Fleshy appendages are mostly red with grey 'branches' or tips.

Feeds on tiny crustaceans.

Males brood about 60 eggs in a large brood pouch on the underside of the trunk before giving birth to live young.

The species is fully protected.

IUCN Red List: Least Concern

EPBC Act 1999: Marine listed

NSW: Listed as protected under the New South Wales Fisheries Management Act.

The skin of I. lumnitzeri is specialised to encourage the growth of the algae it lives amongst, and algae often covers the rings and plates of the body. The algal covering provides very effective camouflage within its habitat. Some individuals monitored over an eight-year period, were observed to live on the same small sections of reef for long periods, up to about 8 months. Individuals occur singly, in pairs or in small groups at night.

Idiotropiscis lumnitzeri differs from Idiotropiscis australe and Idiotropiscis larsonae, in having a shorter and more posteriorly positioned frontal ridge dorsally on the head, a very short trunk, and in having a longer snout (2.2–2.6 in head length, versus 2.8–3.2 in I. australe and 3.7–3.8 in I. larsonae). 

The species is named for Ákos Lumnitzer who collected the type specimens.

Bray, D.J. 2022

Atlas of Living Australia