Tripneustes australiae
Creators: name: McLaren, Emily
name: Sommer, Brigitte
name: Pine, Christopher
name: Miskelly, Ashley
name: Byrne, Maria
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Echinoidea
Camarodonta
Toxopneustidae
Tripneustes
Tripneustes australiae

description: 3.2.2 | T. australiae
Tripneustes australiae has a comparatively narrower subtropicalto-temperate distribution and thermal niche (Figures 1 and 2, Table 1). Tripneustes australiae has a latitudinal range of 8° from Julian Rocks (28°37′30″ S) in the north to Barunguba (Montague Island) (36°13′12″ S) in the south, with the mid-point at 32°25′30″ S near Forster in NSW (Figures 1 and 2, Table SA2). Tripneustes australiae is limited to the southwestern Pacific in the Australia-New Zealand region. The long-term temperature range across this distribution was 15.3°C–26°C, a realised thermal range of 10.7°C. The realised upper and lower limits of T. australiae are 26.6°C and 14.2°C, respectively (Figure 2, Table 1). Outside our region of interest, T. australiae extends to the Kermadec Islands, northern New Zealand in the Pacific (29°42 29.0″ S, 178°08′23.1″ W) (Table SA3).
The distributions of T. australiae and T. g. gratilla overlap in eastern Australia and the Tasman Sea from 35°03′ S to 28°37′ S and 150°13′48″ E to 159°19′1.2″ E (Figure 1). Based on the distribution dataset, T. g. gratilla has a thermal range of 16.3°C–29.97°C, while T. australiae has a range of 15.3°C–26°C. The thermal range of T. g. gratilla is 2.97°C wider than that of T.australiae, and its realised upper limit is 3.8°C higher than T.australiae (T.australiae: 26.6°C; T. g. gratilla: 30.4°C, Table 1). However, despite the contrasting thermal range and upper thermal limits of the two taxa, their realised lower thermal limits are remarkably similar. The realised lower thermal limit of T. australiae and T. g. gratilla were 14.2°C and 14.7°C, respectively, just a 0.5°C difference (Table 1).
3.4.1 | T. australiae
The best habitat suitability model (variables: MD, SST, SWV, and pH) for T. australiae had a high predictive capacity (AUC = 0.996 ± 0.001 SD), indicating the model prediction was reliable. Depth was the best predictor of T. australiae habitat suitability (57.9%), followed by SST (39.7%), SWV (2.4%), and pH (0.1%). Tripneustes australiae habitat suitability was limited to the subtropical and temperate regions of Australia, including the offshore islands Lord Howe and Norfolk (Figure 5). This suggests that depth and temperature act to limit the distribution of T. australiae within these regions of Australia. When future habitat suitability was projected using SPP2-4.5 for the period 2090–2100, the latitudinal range of suitable habitat for T. australiae narrowed and shifted poleward (Figure 5). Suitable habitat also decreased on the offshore islands and increased in the northern part of New Zealand (Figure 5).
description: Published as part of McLaren, Emily, Sommer, Brigitte, Pine, Christopher, Miskelly, Ashley & Byrne, Maria, 2025, Searchin' for Urchins: Utilising Museum Collections and Citizen Science to Assess Species on the Move in the Genus Tripneustes, pp. 1-15 in Journal of Biogeography (e 15092) (e 15092) 52 (5) on pages 7-8, DOI: 10.1111/jbi.15092, http://zenodo.org/record/15304188