Short-spined Seamoth, Pegasus tetrabelos Osterhage, Pogonoski, Appleyard & White 2016


Holotype of the Short-spined Seamoth, Pegasus tetrabelos (CSIRO H 6553–03, 110 mm PCL). Source: Osterhage et al. 2016 PLoS One / DOI: 10.1371/journal.pone.0149415. License: CC BY Attribution

Summary:
A slender cream to medium brown or olive to dark green seamoth, with dark brown to black spots and blotches, four dark saddles on the tail (no dark saddle on 11th tail ring), a triangular pattern of dark brown spots behind the eyes, small dark spots and two sets of large, dark brown spots on pectoral-fin rays. The Short-spined Seamoth has two spines on each side of its tail and P. volitans (bottom) has one.

Cite this page as:
Bray, D.J. 2018, Pegasus tetrabelos in Fishes of Australia, accessed 29 Mar 2024, https://fishesofaustralia.net.au/Home/species/5237

Short-spined Seamoth, Pegasus tetrabelos Osterhage, Pogonoski, Appleyard & White 2016

More Info


Distribution

Known from the Beagle Gulf to off Darwin, Northern Territory, and north eastern Australia from Torres Strait to Broad Sound, Queensland. The species is not known from the Gulf of Carpentaria. Inhabits sandy and muddy bottoms, and has been trawled in depths of 8-45m (mostly above 30 m). 

Features

Dorsal fin 5; Anal fin 5; Caudal fin 8; Pectoral fin 9-10 (usually 10); Pelvic fin I, 2; Tail rings 12; Vertebrae: abdominal centra 7, caudal centra 14, total centra 21.
First 9 tail rings mobile, articulating laterally, remaining 3 rings fused together, attenuated and dorsoventrally flattened; terminodorsal-lateral (tdl) and terminoventral-lateral (tvl) plates each with an anteriorly and posteriorly directed spine; terminal-lateral plates (tl) absent; interpectoral plate (ip) present; single ventral preopercular notch present; rostrum spatulate; carapace with three small posteriorly directed tubercles along each dorsal ridge, one at the centre of each dorsal plate; scales not present on orbit; 5th pectoral-fin ray stouter than other rays.

Colour

Freshly caught specimens: carapace including supraorbital tinged olive to dark green; pectoral fins and dorsal tail rings with small orange-brown spots; single orange-brown spot on base of 1st dorsal ray visible in dorsal view; single orange-brown spots anteriorly on tail rings I and II along both dorsal tail ridges; tail with four dark saddles, no dark saddle on 11th tail ring.. 

In preservative: Reddish brown and cream fading to shades of greyish brown and yellow, respectively. On carapace, pale dorsal ridges less distinct and blending into background colouration; transverse bar less distinct; dorsal lateral plates finely outlined in black. Dorsal plate margins, ventral plate margins posterior to gular plate, and ventral tail margins outlined in light grey. Pectoral and ventral plates darkened to yellowish brown; ventral base of pectoral fins coloured yellow to yellowish brown.

Fisheries

Taken as bycatch in the Australian East Coast Trawl Fishery and Torres Strait Prawn Fishery.

Conservation

The closely-related Pegasus volitans is listed as Data Deficient on the IUCN Red List of Threatened Species. It is taken as bycatch in trawl fisheries throughout its range and is traded in the aquarium industry in some areas, and is sold dried in the Traditional Chinese Medicine industry.

Similar Species

Pegasus tetrabelos differs from the similar Slender Seamoth, P. volitans, in having  anteriorly and posteriorly directed spines on the last dorso-lateral and ventro-lateral plates (vs. absent in P. volitans), terminal-lateral plates absent (vs. present in P. volitans); shorter tail ring XII spine (1.9–3.0 vs. 4.1–5.5% SL in P. volitans), spines on lateral tail ridges demarcate earlier (posterior tail ring IX vs. posterior tail ring X–XI or not demarcating in P. volitans); wider tail ring X (width 4.1–5.0 vs. 3.4–4.0% SL in P. volitans), 4 dark caudal saddles, no prominent saddle on tail ring XI (vs. 5 dark caudal saddles including prominent saddle on tail ring XI in P. volitans); pectoral-fin rays usually 10 (vs. usually 11 in P. volitans); 5th pectoral-fin ray stout (vs. not stouter than adjacent rays in P. volitans); single ventral preopercular notch (vs. double ventral preopercular notch in P. volitans); carapace with three small posteriorly directed tubercles along each dorsal ridge, one at the centre of each dorsal plate (vs. no posteriorly directed tubercles in P. volitans). Lateral keels are often comparatively more defined and posteriorly-directed in P. tetrabelos than in P. volitans.

Etymology

The specific name tetrabelos is from the Greek 'tetra' (four) and 'belos' (dart , arrow), in reference to the four backward-pointing spines on the terminal tail ring (two on each side).

Species Citation

Pegasus tetrabelos Osterhage, Pogonoski, Appleyard & White 2016, PLoS ONE11(3): e7, figs 2, 3a, 4a, 5a, 6a, 7a, 8-10. Type locality: northeast of Dungeness Island, Torres Strait, Australia, 09°46’9” S, 143°09’19” E, depth 19 m.

Author

Bray, D.J. 2018

Resources

Australian Faunal Directory

Short-spined Seamoth, Pegasus tetrabelos Osterhage, Pogonoski, Appleyard & White 2016

References


Osterhage D, Pogonoski JJ, Appleyard SA, White WT (2016) Integrated Taxonomy Reveals Hidden Diversity in Northern Australian Fishes: A New Species of Seamoth (Genus Pegasus).PLoS ONE 11(3): e0149415. PDF Open access doi:10.1371/journal.pone.0149415

Pollom, R. 2017. Pegasus tetrabelos. The IUCN Red List of Threatened Species 2017: e.T101730582A103209434. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T101730582A103209434.en. Downloaded on 30 January 2018.

Quick Facts


CAAB Code:37309004

Conservation:IUCN Data Deficient

Depth:8-45 m

Habitat:Sandy & muddy bottoms

Max Size:14 cm TL

Native:Endemic

Species Image Gallery

Species Maps

CAAB distribution map