Mark Rosenstein Curator

Joined: Oct 31, 2012 Last Active: Jul 19, 2024 iNaturalist Monthly Supporter since December 2021

I'm Mark Rosenstein. Contact me by email to mar at My handle here is pronounced "mar-ACT-win". I live in Cambridge, Massachusetts. If you're visiting the Boston area, message me if you'd like a local hiking companion.

I make a lot of identifications here on iNat, mostly on Indo-Pacific reef fish and North American butterflies and moths. I'm less good these days at including comments when I disagree with another ID. Feel free to ask for more information. I'm pretty good about checking notifications here, though I also travel a lot and am sometimes completely off the net for a couple weeks at a time.

I'm an avid scuba diver, fish geek and underwater photographer. I like to be able to name everything I see on a tropical reef. I've published a field guide to the reef fishes of Fiji, called Fiji Reef Fish. Underwater I also look for nudibranchs, shrimps, and lots of other things. Above water I study birds, butterflies, odonates, lots of other insects and anything else that catches my eye. I'm trying to become a more rounded naturalist and learn some plants too.

Some have asked about my underwater photography. I use a Canon 7DmarkII dSLR inside an Aquatica housing, with dual Retra strobes. I shoot mostly with a 100mm macro lens, though also shoot wide with either a Sigma 17-70mm under an 8 inch dome or Tokina 10-17mm fisheye under a 4 inch dome.

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