Reef Fish ID Tools

There are thousands of reef fish species, but it is impossible to take a thick book under water. Hence, we have no other choice than checking what we remember or have photographed in a fish ID book after getting out of the water. A slow learning process!

With the Reef Fish Trainer, you can learn names of dozens of common fish species in days, hundreds in weeks, before getting wet. Our students use it to train themselves before going on field trips to the Red Sea or Indonesia. When immediately recognising so many fish on their first visit to a reef, the self-satisfaction is overwhelming. And those fish that look unfamiliar, are recognised as something worth taking a picture of for further checking. 

Knowing names also facilitates sharing with others and may make you want to become a citizen scientist and contribute your observations to global initiatives. Some (of many) options are offered by e.g. iNaturalist, reeflex or fishbase. In these online platforms experts and private enthusiasts with any level of expertise share their pictures and discuss identifications. We encourage you to use these sites as your digital encyclopaedia and ID assistants.

Knowing many reef fishes by name will add a rewarding new dimension to your dives and contributes to global biodiversity research.

There has never been a better time to start than now.

Biologists like us prefer scientific "Latin" names because they are the scientific standard. We keep them up-to-date by following Eschmeyer's Catalog of Fishes, which is also adopted by iNaturalist. The latter also shows popular names in many languages.

If you do not want to bother with scientific names, focus on the popular English names, which we added to the Reef Fish Trainers.

We took popular names from iNaturalist where available. Just realise that they can vary within and between countries. Future versions with popular names in German or regional languages such as Arabic for the Red Sea or Bahasa for Indonesia are on our wish list.

It is easiest to start the process on a computer (even if you intend to use it mostly on your cell phone, as most do)

Step 1: Download and install the freely available Anki app: https://apps.ankiweb.net (Windows or Mac). Anki is the tool that allows you to import and run digital flashcard decks prepared for you by developers like us.

Step 2: Select, download, and unzip the preferred deck from the list below (file type *.apkg).

Step 3: Open the Anki app. Choose File → import → the deck you downloaded. The deck now appears in the list on Anki's starting page. You can have multiple decks in parallel on your devices.

Step 4: Prepare access from your smartphone or tablet by clicking “Sync” at the top of the main Anki window on your computer. Set up a (free) Anki account to make that possible. Sign up. Having this online account will assure that whatever you have learned on whatever device will be synchronised between all your devices.

Step 5: Now you install the Anki app on your smartphone/tablet.
Android: visit the playstore and search for AnkiDroid Flashcards (free app). Install it and synchronise with your AnkiWeb account by pressing “Sync”. The deck will automatically be downloaded on your smartphone.
Apple: The iPhone/iPad app costs a little in the AppStore (29.99 €). If you do not wat to pay, log in to AnkiWeb in a web browser on your device (e.g. Safari).

Step 6: You are now ready to start learning
- Open Anki as an app or login with your username on the internet site in your browser (any device).
- Click on your preferred Reef Fish Trainer deck to start or continue an ongoing learning process.
- Open "deck options" (cog wheel on the lower right of the Anki window). Click Study Options.
- Set Daily Limits "New cards/day" to 20. Start with prudence. Increase this number later if you want.
- Under “Display Order”, set “New card gather” order to “Random cards”.
- The other settings are less relevant. Explore them once you feel comfortable.

Go back, click the cogwheel again, open “Custom Study”
- Here, you can e.g. “Learn new cards with certain tags”. Use tags to define a subset you want to focus on. See section “What are tags and why should I use them?”.
- At the bottom, you can also increase today's new card limit. Do not overdo it. Regularly learning a small number of cards per day better than too many on irregular days.  

_{Note: Things may look a bit different on your system. No worries. You'll find what you‘re looking for by checking around or consulting the Anki online help.}

Tags define subsets in a deck. Learning subsets allows you to focus on groups of species rather than "all at once", which may be too much if you start from zero. 
This is how to use tags:
- Open your target Anki deck.
- Open deck options (cog wheel on the lower right). Click Custom Study.
- Select “Learn new cards with certain tags”.
- Select tags to include or exclude. Combining tags is possible.
- “Custom Study” will now appear as a new “virtual” Deck in your man list of decks. As long as you keep learning this deck, you only see what you specified in Custom Study.
 

The current decks offer different types of tags.

- 1-pic-per-species reduces the dataset to one image of all the species (and sexes/stages if applicable). Good start, but beware the drawback: You learn names without seeing any diversity in colour or stage of that species.

- Abundancy tags reduce the pictures to particularly common (or rare) species.

- Eco or Set tags refer to subsets of species that share a similar ecology or look.

- Family: Including or excluding fish families allows you to follow your personal interest.

To help people recognising fish with their own eyes, we realised how essential it is to not use artificial light for photography.

Hence, In contrast to what most underwater photographers will urge you to do, we refrain from using artificial light. With the amazing sensitivity of modern digital cameras, image stabilisation and ISO-noise reduction, natural light is all you need. To correct for the underwater blue-green colour cast, we use manual white balance or automatic underwater white balance  with or without the addition of colour-correcting filters to capture fish colour "as seen by a human diver". Depending on location and equipment, this works down to a depth of at least 30 m.

Of course, professional pictures taken with a flash often look more spectacular, but usually because of unnaturally strong colour saturation, excellent detail, and maximal depth-of-field (diaphragm nearly closed). Yet, this does not represent how a photographer discovered the fish with their own eyes! A problem with flashguns is that they more often than not add terrible artefacts such as strong reflections, dark backgrounds, exaggerated brightness for species that are essentially black, or wrong colours for fish at distances beyond the range of the current flashgun setting. Consequently, photographs in many fish books look quite different from how that same fish appeared to the person who photographed them in the field.

Since it is our goal to allow people to discover and identify a fish before taking a picture, we put effort into showing them as they appear naturally to you or anyone else.

Just in case you wonder. Of course, we use artificial light too, but only when it really gets too dark. We also agree that certain diagnostic features are easier to capture with artificial light. Yet, we find that it is underestimated how many diagnostic traits for visual field identification are more reliably represented by "natural light" photographs.
 

Many fish species change colour in seconds, a fact that is ignored in most fish books. This is particularly spectacular in some genera of the Epinephelidae (Groupers), Lethrinidae (Emperors), Siganidae (Rabbitfishes), and more. 

In the Labridae (Wrasses and Parrotfishes) intermediate colour forms from juveniles turning into initial-phase individuals (IP) turning into terminal-phase (TP) individuals make field identification a serious challenge. Moreover, colour also varies within stages. This makes Parrotfishes in particular a true challenge for visual field identification.

This is why our Reef Fish Trainers contains pictures of as many of the colour forms as we have been able to document for any species to date. Environmental colour variation caused by depth, distance, time of day, visibility and cloud cover comes on top. Hence, also for species that show hardly any intrinsic colour change, we show multiple pictures where we can to  cover this environment-dependent variation.

Showing natural colour variation fills a gap not covered by most field ID books.

Despite planned updates, we do not intend to cover "all" fish species of the Red Sea or Indonesia - that is too much, and misses the point as you would learn mainly species that you will never see! Just be aware that there are very many additional, but very rare or new species around. These tend to look similar to the ones you are already familiar with. Hence, once you start to take fish identification serious, it is important to regularly cross-check with the all other sources. Here are the most important ones:

Sources for the Red Sea

Ryanskiy (2022) Red Sea Marine Life
The famous unterwater photographer Andrey Ryanskiy compiled the most complete picture book of fishes and other organisms of the Red Sea to date. His recent book is currently our first choice for rapid identification. Available as a pdf or iBook, it covers +810 fish species. The text is condensed. Excellent value for money.

Heemstra et al. (2022) Coastal Fishes of the Western Indian Ocean
A 5-volume fish encyclopaedia that includes the Red Sea. Contributions from hundreds of scientists. Free download. Made for specialists and useful for all. Many drawings and pictures, many useful identification keys. A game changer for this part of the world, but perhaps too much detail if “reef fishes” is a new area for you.

Lieske & Myers (2004) Coral Reef Guide Red Sea
The "classic of the past" with which most of us grew up. It inspired generations of Red Sea enthusiasts. In 2023, this book is definitely outdated in species naming and picture quality, but still a source we continue to consult. Translated in many languages.

Eagerly expected: Bogorodsky, Randall and Krupp - Coastal Fishes of the Red Sea
We are very excited about the pending publication of this book, which promises to be nothing less than the most comprehensive overview of the coastal fishes of the Red Sea. Sergey Bogorodsky is the authority of Red Sea fish systematics. The book is expected to offer extensive literature, descriptions, diagnostic traits, details about live stages, biology and distribution, and multiple pictures per species. It is at the top of our wish list. 

Sources for Indonesia

Details to follow - but for now, any book with Gerald R. Allen as the main or contributing author is an excellent starting point. Andrey Ryanskiy published an excellent picture book Reef Fishes of the Coral Triangle in 2019 that we like a lot and consult often.

Fish ID internet sources

iNaturalist – reeflex – fishbase – Reef Life Survey – Fishes of Australia – Australian Museum – etc.
Let us know if we missed important non-commercial, scientific sources.

Matteo Santon made me aware of the "world of Anki" as a perfect tool to train students to recognise fish species in the field. Together, we made the first desk for the Red Sea in 2018. It all started from there.

Most pictures are taken by Nico Michiels. He is in charge of confirming species identification, naming and optimising images, updating the database and producing the Anki decks. Based on these materials, the development of improved field identification guides of specific fish groups is the subject of Bachelor and Master theses, e.g. Fishes of North-Sulawesi (Robin Kraft), Parrotfishes (Laura Uhl), Amblyeleotris shrimp gobies (Pia Merkel), “twin” species (Tabeo Bollinger), and Surgeonfishes (Julia Kastner).

Thanks to many students and reef fish enthusiasts for contributing their pictures. They are constantly updated and acknowledged in the pdfs and ANKI decks.

Mario Schädel developed the Python and Latex scripts to produce the pdf picture catalogues (Details). Ken Werner optimised the work flow. David Kleindiek produced the “fish renamer” - a tool to quickly and efficiently rename pictures to include all relevant data in the image file name (Details).
 

Copyright statement: CC BY-NC

All images are property of the Animal Evolutionary Ecology professorship at the University of Tübingen (represented by Nico K. Michiels) under copyright license CC BY-NC. Use for non-commercial, educational purposes is free, assuming you mention the source and photographer. 

Use for commercial purposes is prohibited without explicit consent. 

The use of the Anki Reef Fish Trainer deck for personal training purposes is free.

We appreciate feedback!