Long-term home ranging in the large sea cucumber, Holothuria fuscopunctata

Abstract

Long-term movements of adult marine animals predicate spatial management measures. Sea cucumbers are intensely exploited worldwide, yet few studies have assessed their long-term movement potential. Elephant trunkfish, Holothuria (Microthele) fuscopunctata, is a large coral reef holothuroid. At four sites at Lizard Island, northern Great Barrier Reef, we photographically marked and georeferenced 36 H. fuscopunctata, ranging 1.4–5.1 kg in weight. In broader searches one year later, we recaptured 92% of the animals. Their displacements were comparable among sites and averaged 8.7 m yr−1. None of the movements could be characterised as nomadic; the maximum displacement was 21 m. Contrary to expectations, smaller animals tended to roam further than larger animals (p = 0.025). Our study shows that certain large-bodied sea cucumbers might not displace far over annual timescales. This empirical evidence of home ranging reshapes our understanding of echinoderm mobility and reveals a behaviour that would exacerbate Allee effects at low population densities.

Dispersal patterns of sandfish (Holothuria scabra) larvae in Manus Province, Papua New Guinea

“…Because sea cucumbers are relatively sedentary, small LMMAs are likely to be sufficient for protecting their spawning stocks. For example, some large-bodied species such as the elephant trunkfish (Holothuria fuscopunctata) move less than 10 m on average over annual timescales (Purcell et al, 2023). Movement studies on H. scabra indicate that H. scabra will cover a total distance of 2-8 m per day and have home ranges of<0.05 km 2 (Lee et al, 2018).…”