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The largest known reef manta ray (Mobula alfredi) population in Africa has been monitored for more than 20 years at several locations on the coast of the Inhambane Province in southern Mozambique. Nonetheless, before this study, little had been reported on the population dynamics of M. alfredi from Závora, a remote bay in the region. Photographic mark-recapture was used to investigate the size and structure of M. alfredi that aggregate at "Red Sands," a reef cleaning station in Závora Bay. An 11 year photographic data set was used to identify 583 M. alfredi individuals between 2010 and 2021. More than half of M. alfredi individuals were resighted at least once, with most encounters (up to 18 for one individual) occurring during the peak sighting period in July-November each year. An even sex ratio was observed, 44% females and 50% males, with no significant difference in resightings between the sexes. Pollock's robust design population models were used to estimate annual abundance, emigration, annual apparent survival and capture probability at Red Sands from July to November over a 6 year period (2016-2021). Abundance estimates varied year to year, ranging from 35 (95% c.i. [30, 45]) up to 233 (95% c.i. [224, 249]) M. alfredi individuals. Given the seasonal affinity of M. alfredi observed at Red Sands, this study highlights the importance of understanding fine-scale site use within the larger home range of this population to develop local management strategies.

Opportunistic in-water and aerial surveys in South Africa and the analysis of contributed citizen science data have extended the known range of reef manta rays Mobula alfredi along the eastern coast of Africa by 140 km (to Mdumbi Beach) and verified the first transboundary movements for the species. Additionally, six new long-range dispersal records have provided evidence of connectivity with the M. alfredi population off the Inhambane coastline of Mozambique. Five of these records captured one-way movements, the longest of which was an individual that traveled 505 km from Praia do Tofo to Sodwana Bay with 301 days between sightings. A single individual made a return trip between Závora, Mozambique and Sodwana Bay, South Africa (a total distance of ~870 km). These findings support the Convention on Migratory Species (CMS) listing for the species, suggesting regional transboundary management units are warranted for this wide ranging elasmobranch. This article is protected by copyright. All rights reserved.

Reef manta rays (Mobula alfredi) are social elasmobranchs that have structured societies and actively interact with preferred social partners. Being able to detect cues and signals produced by conspecifics is vital in enabling social behavior. Many elasmobranch species communicate via body and fin postures, but it is not yet known if or how mobulid rays communicate or respond to cues produced by conspecifics. These rays have specialized cephalic lobes that are highly flexible and used in feeding, but may have other functions such as gestural communication. In this study, we developed a standardized method to assess manta ray behavior in the wild via focal sampling and frame-by-frame video analysis. From observations recorded at cleaning stations in Raja Ampat, West Papua, we described various types of cephalic lobe positioning and movements made by free-ranging M. alfredi and investigated these in different behavioral contexts. We found that cephalic lobe curls were modulated when approaching both conspecifics and human divers, as well as during interactions with cleaner fish, suggesting that these lobes may be used in sensing water movements, olfactory sensing, and/or gestural communication. Cephalic lobes were moved independently of one another, but we found no evidence of individual laterality. The lack of chemosensory capacity on the lobes suggests that gestural communication is the most likely function, but further research is required to determine this. These results are informative in understanding the function of gestural communication in manta ray social interactions and add to our growing understanding of elasmobranchs’ sophisticated social behavior. Social animals rely on communication and cues produced by conspecifics to respond to opportunities and threats. Many elasmobranch species use body and fin postures as gestural signals during competitive, courtship, and other social interactions. Reef manta rays (Mobula alfredi) are social elasmobranchs that form groups in near-shore, shallow water habitats. They possess paired, flexible cephalic lobes positioned on the side of the head which are specialized for feeding but may have a variety of functions. Here, we describe, quantify, and suggest likely explanations for the movement and positioning of cephalic lobes during various manta ray social behaviors, including conspecific, human, and cleaner fish interactions. Our results suggest that lobe movements may be used in detecting water movements, olfactory sensing, and/or gestural communication, and are an important aspect of social behavior in this species.

To determine a dose of nebulized formoterol fumarate inhalation solution (FFIS) comparable to that of the marketed formoterol fumarate dry powder inhaler (FA, 12microg), two crossover studies were conducted in subjects with COPD. Study 1 was a single-dose, double-blind, double-dummy dose-ranging study in which 47 subjects were randomly assigned to treatment sequences that evaluated the bronchodilatory effects of FFIS 2.5, 5, 10, 20, and 40microg, FA, and placebo over 12h. Mean FEV(1) AUC(0-12) following FFIS treatment ranged from 1.3 to 3.0l/h in a dose-related manner, with equivalent values (2.3l/h) for FFIS 20microg and FA. Results for other spirometric measures, including peak and trough FEV(1) and absolute change in FEV(1) by timepoint, confirmed the comparability of FFIS 20microg and FA. Study results with the nebulized formulation supported the rapid time to onset of bronchodilation with FFIS 20microg (3.9 and 2.2min imputed for 15% and 12%/200ml response, respectively). Study 2, a single-dose, open-label crossover study, was conducted to establish the pharmacokinetic (PK) profile of nebulized formoterol and confirm comparability to FA. Thirteen subjects were randomly assigned to treatment sequences with FFIS 10, 20, and 244microg and FA with a 5-14-day washout period between each treatment. Formoterol levels were assessed from blood and urine collected pre-dose and over a 24-36-h period after dosing. Pharmacodynamic (PD) measures included clinical laboratory and ECG measures pre-dose and over a 24-h period post-dose. FFIS 244mug was rapidly absorbed with a T(max) of 12min and t(1/2) of 6.1h. Data from other doses were sporadic due to assay sensitivity. The mean amount excreted (Ae) in urine suggested linear kinetics and confirmed the comparability of FFIS 20microg and FA. Mean serum potassium decreased and mean serum glucose increased transiently in a dose-dependent manner following treatment. No clinically significant ECG changes were observed; mean heart rate increased after treatment with FFIS 244mug by up to 6bpm. Findings from dose-ranging and PK/PD studies confirmed that a 20microg dose of FFIS was comparable to formoterol fumarate delivered by dry powder inhalation (12microg) and established the dose proportionality and linear kinetics of formoterol fumarate delivered by nebulization.