## 1 Introduction  
Comprehensive knowledge of the movement ecology and habitat use of threatened species is essential for developing effective conservation and management strategies aimed at their protection [1]. The reef manta ray _Mobula alfredi_, currently listed as vulnerable (VU) on the IUCN Red List of Threatened Species, is distributed throughout the Indo-Pacific region [2]. Globally, populations of reef manta rays have experienced significant declines over the past five decades, primarily due to fishing pressures, including bycatch and targeted fisheries [2, 3].  
In 2014, the reef manta ray, along with the oceanic manta ray (_M. birostris_), was granted full protection across Indonesia by the national government, following a landmark initiative by the Raja Ampat recgory government which established Raja Ampat as Southeast Asia's first shark and ray sanctuary in 2012 [4, 5]. Despite this legal protection, knowledge of the population dynamics and movement ecology of manta rays in Indonesia remains limited. Systematic surveys and data collection, primarily using photographic identification, began between 2011 and 2013 in four key regions (Berau in East Kalimantan, Nusa Penida off the coast of Bali, Komodo in the Strait between Flores and Sumbawa, and Raja Ampat in Southwest Papua), which have since all been confirmed as critical habitats for manta rays [6, 7, 8, 9]. Additionally, a few studies have employed passive acoustic telemetry to investigate site fidelity, seasonal movements, and spatial connectivity of reef manta rays in Komodo [10] and Raja Ampat [11, 12]. However, these studies were constrained by the limited size and spatial extent of the acoustic receiver arrays, as the tagged manta rays were only detected within the network, leaving their movements beyond the array untracked.  
Satellite telemetry provides a powerful tool for tracking the horizontal movements of aquatic animals using light-level geolocation, the Argos satellite network, and the global positioning system (GPS), free from the limitations imposed by acoustic receiver array networks [13]. This technology has been widely applied to monitor the spatial movements of marine animals across various taxa [14, 15], including manta rays, e.g., [16]. Studies employing satellite telemetry on reef manta rays across their distribution range have revealed predominantly restricted movement patterns, with individuals generally remaining within their tagging regions and exhibiting high residency near coastal areas, as observed in populations such as those in Dungonab Bay and Mukkawar Island National Park, Sudan [17]; northern Farasan Banks, the Red Sea [18]; New Caledonia [19]; western Australia [20]; eastern Australia [16]; and Seychelles [21].  
In Indonesia, satellite telemetry studies on manta ray movement patterns and habitat use have been reported exclusively from Raja Ampat by [PERSON] et al. [22] and [PERSON] et al. [23]. However, these two studies focused only on oceanic manta rays and juvenile reef manta rays, respectively. The current study aims to provide scientifically robust recommendations for enhancing management and conservation strategies for the reef manta ray, a globally vulnerable species within Indonesia, the world's largest manta ray sanctuary. Based on satellite telemetry data, we present findings on the horizontal movement patterns, habitat use, and home ranges of reef manta rays from four key regions--Berau, Nusa Penida, Komodo, and Raja Ampat. Additionally, we discuss the potential drivers influencing these movement patterns and the broader conservation and management implications of our results.