Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives

Abstract

The aim of this 14 year study was to elucidate the entire courtship and mating behaviour of manta rays Mobula alfredi and M. birostris using behavioural observations, video and photographic records. From 2003 to 2016, over 11,000 surveys were undertaken at known manta ray aggregation sites in the Maldives to record any observed manta rays reproductive activity. From 47,591 photo-ID sightings, 4,247 individual M. alfredi were identified and 226 individual M. birostris from 229 photo-ID sightings, all recorded at 22 atolls across 265 different sites. Courtship activity was observed on 206 surveys at 30 different sites. A total of 229 courtship events were recorded, with 90% (n = 205) of them occurring at cleaning sites. The observed courtship activity was categorised into seven distinct stages which are described in detail: initiation, endurance, evasion, pre-copulatory positioning, copulation, post-copulatory holding and separation. Photographs provide the first scientific record of the entirety of manta rays courtship and mating. Both M. alfredi and M. birostris appear to engage in the same elaborate courtship rituals, exhibiting the same behaviours during all stages of the courtship and mating process.

Research Priorities to Support Effective Manta and Devil Ray Conservation

“…The reproductive biology of mobulid rays is known mostly from the reef manta ray (M. alfredi). Courtship and copulation in reef manta rays are common around cleaning stations and reef habitats (Marshall and Bennett, 2010;Deakos et al, 2011;Deakos, 2012;Stevens, 2016;Stevens et al, 2018b). Observations of courtship and mating remain rare in other mobulid species (Yano et al, 1999;Duffy and Scott, 2017;Stevens et al, 2018a).…”

“…In several mobulid species, reproductive activity peaks seasonally and may occur more often at social aggregation sites such a seamounts or cleaning stations (Yano et al, 1999;Marshall and Bennett, 2010;Stevens, 2016;Stevens et al, 2018b). However, significant knowledge gaps remain in our understanding of mobulid courtship and mating behavior.…”

Contrasting Habitat Use and Population Dynamics of Reef Manta Rays Within the Nusa Penida Marine Protected Area, Indonesia

“…Manta ray behavior was assessed from sighting data based on mouth and cephalic fin positioning, the presence and absence of cleaner fish, and records of social interactions, including mating trains as described by Marshall and Bennett (2010), Deakos (2012), Jaine et al 2012, and Stevens et al (2018). Based on these previous studies, behavior was categorized into four mutually exclusive categories: foraging, cleaning, cruising, and courtship ( Supplementary Figure 4).…”

“…'Cruising' manta rays were those sighted with closed mouths and rolled up cephalic fins. 'Courtship' behavior was recorded when several male manta rays pursue a mature female (in the absence of foraging behavior), or when two or more individuals gave acrobatic displays as described by Stevens et al (2018).…”

Current strength, temperature, and bodyscape modulate cleaning services for giant manta rays

“…In Mozambique, reef manta rays are known to clean during moderate strength currents because these conditions are favourable for hovering over cleaning stations (Rohner et al 2013). Hovering may facilitate giant mantas' interactions with cleaners since cleaning typically occurs near spatially finite structures that are known as 'focal points' (Acebes et al 2016;Stevens et al 2018). Hovering is also likely to be an energetically efficient strategy that makes giant manta rays more accessible to cleaners and, therefore, more attractive as clients (Acebes et al 2016;Fish et al 2018).…”