Dear Marmam readers, On behalf of my co-authors, I am very pleased to announce the publication of our paper. Yang L, Sharpe M, Temple AJ, Jiddawi N, Xu X, Berggren P (2020) Description and classification of echolocation clicks of Indian Ocean humpback (*Sousa plumbea*) and Indo-Pacific bottlenose (*Tursiops aduncus*) dolphins from Menai Bay, Zanzibar, East Africa. PLoS ONE 15(3): e0230319. https://doi.org/10.1371/journal.pone.0230319 *Abstract*: Passive acoustic monitoring (PAM) is a powerful method to study the occurrence, movement and behavior of echolocating odontocetes (toothed whales) in the wild. However, in areas occupied by more than one species, echolocation clicks need to be classified into species. The present study investigated whether the echolocation clicks produced by small, at-risk, resident sympatric populations of Indian Ocean humpback dolphin (*Sousa plumbea*) and Indo-Pacific bottlenose dolphin (*Tursiops aduncus*) in Menai Bay, Zanzibar, East Africa, could be classified to allow species specific monitoring. Underwater sounds of *S. plumbea* and *T. aduncus* groups were recorded using a SoundTrap 202HF in January and June-August 2015. Eight acoustic parameters, i.e. -10 dB duration, peak, centroid, lower -3 and lower -10 dB frequencies, and -3 dB, -10 dB and root-mean-squared bandwidth, were used to describe and compare the two species’ echolocation clicks. Statistical analyses showed that *S. plumbea* clicks had significantly higher peak, centroid, lower -3 and lower -10 dB frequencies compared to *T. aduncus, *whereas duration and bandwidth parameters were similar for the two species. Random Forest (RF) classifiers were applied to determine parameters that could be used to classify the two species from echolocation clicks and achieved 28.6% and 90.2% correct species classification rates for *S. plumbea* and *T. aduncus*, respectively. Both species were classified at a higher rate than expected at random, however the identified classifiers would only be useful for *T. aduncus* monitoring. The frequency and bandwidth parameters provided most power for species classification. Further study is necessary to identify useful classifiers for* S. plumbea*. This study represents a first step in acoustic description and classification of *S. plumbea* and *T. aduncus *in the western Indian Ocean region, with potential application for future acoustic monitoring of species-specific temporal and spatial occurrence in these sympatric species. The paper is open access and freely available to read or download at: https://doi.org/10.1371/journal.pone.0230319 If you have any questions, please do not hesitate to email me at yllxmu@gmail.com All the best, Liangliang -- Dr. Liangliang Yang Postdoc Research Associate Marine Megafauna Lab School of Natural and Environmental Sciences Newcastle University, UK Email: yllxmu@gmail.com Phone: +44 (0)1912085091