Archivos de diario de enero 2023

04 de enero de 2023

Silverstoneia flotator vs. Allobates talamancae in Costa Rica

Costa Rica has 7 species of Poison Frogs. Most are very easy to separate based on appearance and/or distribution.

But 2, Silverstoneia flotator and Allobates talamancae, which are actually in completely different families are often confused.

I spent some time doing research on distinguishing these frogs, one great reference is The Dendrobatid Frogs of Central America (1968) by Jay M. Savage*.

While amazingly superficially similar, Silverstoneia flotator has an "oblique lateral stripe" from the groin to the eye that is actually lacking in Allobates talamancae. In Allobates talamancae there is a dorsolateral stripe which looks very similar but it originates above the leg (not in the groin and thus not oblique/diagonal across the body) and extends passed the eye. I've found the best way to tell if you're looking at a oblique lateral stripe (Silverstoneia flotator) or a dorsolateral stripe (Allobates talamancae) is to look at the end that hits the leg/groin. If it hits the groin (oblique lateral stripe) there will usually be some black side of the body color above the stripe visible before you get to the lighter brown dorsal top of the frog. If it hits the leg above the groin (dorsolateral stripe) the stripe itself will be the border between the black side of the body color and the lighter brown dorsal top of the frog.

Also male Allobates talamancae have gray/black throats/bellies which are white in Silverstoneia flotator. And Allobates talamancae are a bit larger (snout to urostyle lengths of 17–24 mm vs 14.4–18 mm in Silverstoneia flotator). Once you go south into Panama, there are other species in the mix (Silverstoneia nubicola, Colostethus pratti, Colostethus latinasus, Colostethus inguinalis, Colostethus panamansis) that make things a bit more complicated. I might update this post with them at some point.

Alot of poison frogs mimic one another to take advantage of learned poison avoidance by predators. I wonder if thats whats going on here, because for being in different families, Silverstoneia flotator and Allobates talamancae sure do look amazingly similar!

Thanks to @wasatch_hunter for posting the awesome photos I made use of here

*The names have changed a bit since the Savage paper, here's a mapping to the current taxonomy
Savage -> current
Dendrobates auratus -> Dendrobates auratus
Dendrobates granuliferus -> Oophaga granulifera (genus change)
Dendrobates pumillo -> Oophaga pumilio (genus change)
Dendrobates speciousus -> Oophaga speciosa (genus change, also extinct)
Dendrobates minutus -> Andinobates minutus (genus change)
Phylobates lugubris -> Phyllobates vittatus/Phyllobates lugubris/Andinobates claudiae (split)
Colostethus inguinalis -> Colostethus inguinalis/Colostethus panamansis (split)
Colostethus latinasus -> Colostethus latinasus
Colostethus pratti -> Colostethus pratti
Colostethus nubicola -> Silverstoneia nubicola/Silverstoneia flotator (split and genus change)
Colostethus talamancae -> Allobates talamancae (genus change)

Savage doesn't include these species, I'm not sure why, maybe not discovered yet?
Andinobates geminisae
Andinobates fulguritus
Oophaga vicentei

Publicado el 4 de enero de 2023 21:38 por loarie loarie | 6 comentarios | Deja un comentario

11 de enero de 2023

Tailless Whipscorpions - Amblypygi

This post is to help me get my head around the Tailless Whipscorpions (Amblypygi) prompted by @sjl197's generous help on one of my obs today.

Global overview

There are 5 families:

Paracharontidae

Just 1 species (Paracharon caecus) from west Africa

Charontidae

1 genus Charon in Southeast Asia/Oceania

Phrynichidae

7 genera:
Damon (Africa)
Euphrynichus (Africa)
Musicodamon (Africa)
Phrynichodamon (Africa)
Phrynichus (Palaeotropics)
Trichodamon (South America)
Xerophrynus (Africa)

Phrynidae

Restricted to the Neotropics aside from Phrynus exsul on Flores/Rinca Islands in Indonesia:
Acanthophrynus (Mexico)
Heterophrynus (South America)
Paraphrynus (Mesoamerica)
Phrynus (Mesoamerica & Flores/Rinca in Indonesia)

Charinidae

The most speciose family with the broadest geographical distribution (see Miranda et al 2022).
Charinus (a pantropical distribution)
Sarax (arcs from Greece through Asia)
Weygoldtia (around Vietnam)
Catageus (1 sp, Myanmar)

United States

In the US there are 4 regular species all in Phrynidae in the 2 genera Paraphrynus (2 sp Florida and Arizona) and Phrynus (2 sp Florida and Texas). The 2 genera can be separated based on shape of the pedipalp tibial spines (see figs 4 & 5 here). There are 2 spines between the longest 2 spines in Paraphrynus (thank you @mason_s) and just 1 spine between the longest 2 spines in Phrynus (thank you @fmcghee)

Costa Rica

In Costa Rica there are also 4 species in the same 2 genera Paraphrynus and Phrynus.
@sjl197 says that in Costa Rica what that document calls Phrynus gervaisii are now considered Phrynus barbadensis (is there a source for that?). Which would make the 4 Costa Rica species:
Paraphrynus laevifrons
Phrynus barbadensis (rather than Phrynus gervaisii)
Phrynus pseudoparvulus
Phrynus whitei

Questions

At the time of this writing I have a couple of questions I want to look into more, mostly to get a handle on North American Amblypygi:

1) How do you distinguish Charinus from Phrynidae in the Americas where they both occur?

2) How do you distinguish Phrynus exsul (the only Old World member of the otherwise New World family Phrynidae) from other Charon species that occur on Flores and Rinca Islands?

3) How do you distinguish the two New world members of Phrynichidae (Trichodamon froesi and Trichodamon princeps) from each other. Are the strikingly wide pedipalps a good way to distinguish them from Phrynidae and Charinus?

4) US and Costa Rica species are pretty straightforward, but what about the ones in between (e.g. Mexico, Guatemala, Belize, Honduras, El Salvador, Nicaragua)? Are there no Charinus species in these countries? (hard to tell from Miranda et al 2022 Fig 2)

5) Whats going on in the Caribbean? (there it does look like alot of Charinus species are involved)

To dos

1) Read this paper on Colombia as mentioned here

2) Coarsen these obs of Phrynus operculatus that occur south of Guatemala to fix incorrect IDs and/or engage in good conversations if people think this species does extend this far south

Publicado el 11 de enero de 2023 00:53 por loarie loarie | 1 comentario | Deja un comentario

13 de enero de 2023

Embedding annotated images in journal posts

Someone asked me recently how I embed annotated images in my journal posts, so I thought I'd make this quick post to explain how.

Finding photos

My general approach is to read papers to get a sense for important characters and then find examples in iNat photos that show those characters. When finding iNat images, I always choose once that have licenses so I just have to attribute the observer rather than contacting them for permission. Generally, look for the 'cc' rather than the 'c' on photos you want to use


From the brows photos section of a taxon page you can also search for only photos with certain licenses

Once you find a photo you like, just right click to save locally or just do a screen grab (shift-command-4 on a Mac).

Annotating images

I have a copy of Adobe Illustrator I usually use, but because Illustrator isn't free, for the examples in this post I used Inkscape which is essentially a free version thats perfectly fine. I pretty much just drag photos I've downloaded in and then layer on text and little arrows (just 3 cornered polygons) to point at things. You can save the image in vector format which will keep all the elements separate, but export a png version to use in your journal post.

Uploading images to the web

iNaturalist doesn't let you upload images to journal posts directly so I upload them to Flickr which is free for a certain number of photos that is way higher than I will probably ever use.

Embedding images in journal post

To embed the photos in your journal post, click on the curved arrow on Flickr and choose 'embed' and grab the little bit of text it shows

You can past this whole thing into your journal post

But I make 2 changes. First, I get rid of the anchor tab wrapper to and just keep the img tag bit in the middle so it doesn't link back to Flickr. Second, I replace the width with a percentage and just remove the height and alt tag. This leaves me with this:

When you save and preview or publish your journal post that will render like an image.

I'd love to see more people making journal posts with tips on how to distinguish tricky species - so if you're trying to do that, I hope this helps!

Publicado el 13 de enero de 2023 09:18 por loarie loarie | 0 comentarios | Deja un comentario

Identifying Madagascar Ghost Crabs

According to Sakai & Türkay, 2013, Madagascar has 5 sp. of Ghost Crab (although @martinmandak
found
a 6th in the distinctly pink-kneed O. ryderi on an island thats technically part of Madagascar). The are:
O. ceratophthalma
O. cordimana
O. pallidula
O. pauliani
O. madagascariensis

The first 3 have very large distributions across the Indo-pacific.

O. ceratophthalma is the only one with 'horns' (ocular styles) which makes them easy to spot (but careful, only adults have horns, juvenile ghost crabs are pretty much hopeless to get to species unless you can examine characters almost never visible in iNat photos (reproductive organs or the stridulating ridge on the palm of the hand).

The large claw of both O. cordimanus and O. pallidula are relatively smooth. I'm still not confident what O. pallidula looks like so I'm not totally sure how to separate these (lots of mis-ID'd O. pallidula photos out there I suspect). But if you look in Eastern Australia where only O. ceratophthalma and O. cordimanus are present you'll get a good feel for what O. cordimanus looks like.

The remaining two species are Madagascar endemics or close to that (O. madagascariensis is also found across the the Mozambique Channel along the coast of southern Africa). I wasn't sure how to identify them, but I was aware of some observations of 2 distinctive ghost crabs on Madagascar that I hadn't seen from anywhere else on iNat. So I decided to try to reconcile them with Sakai & Türkay, 2013 and the type specimens (here and here

Bumps on the back

O. madagascariensis has larger bumps (tubercles) on the back that are pretty much the same size across the back. In contrast, O. pauliani has larger bumps towards the side edges of the back and smaller bumps in the middle. This is pretty easy to spot in several of the more in-focus close up photos

Bumps on the larger claw

Both O. madagascariensis and O. pauliani have claws with much larger bumps (tubercles) on them than O. cordimanus or O. pallidula. But of the 2, O. pauliani has a much rougher looking claw with larger fewer bumps. The bumps on O. madagascariensis are smaller and aligned more in rows especially towards the tip of the claw. O. pauliani just gives the impression of a much more tricked out claw than O. madagascariensis (annoying the Sakai & Türkay, 2013 specimen is missing its claw)

Color

Sakai & Türkay, 2013 mentions both of the characters above and they are visible in the specimens. But as usual they don't mention the distinctive color patterns which are so easy to spot in iNat photos but I guess don't preserve well in specimens. In this case adult O. pauliani seem to have striking colors with pale heads with bright orange eyestalks and mouthparts. O. madagascariensis seems much more uniformly sandy colored by comparison.

I feel pretty confident in my conclusions, but would definitely appreciate hearing from the expertise of others. For both of these crabs there don't appear to be any labeled photos of living animals on the web, which is kind of depressingly shocking, so I could be wrong in my logic linking these living animals to the specimens and museum descriptions. But assuming I'm right, its exciting to be able to finally add labels to these striking photos - especially O. pauliani which we have a few obs of and they are beauties for sure!

Publicado el 13 de enero de 2023 09:54 por loarie loarie | 0 comentarios | Deja un comentario

15 de enero de 2023

Identifying Australian Ghost Crabs

According to Sakai & Türkay, 2013, Australia has 5 sp. of Ghost Crab:
O. ceratophthalma
O. cordimana
O. pallidula
O. fabricii
O. convexa

Rae, 2018, The distribution and trophic ecology of Golden ghost crabs (Ocypode convexa) maps all of them except Ocypode pallidula which they describe as "constrained to islands off the Queensland coast, such as Lady Elliot and Heron Islands"

Along with O. pallidula, O. ceratophthalma and O. cordimana are widespread and distinctive. The 2 species endemic to Australia are the Golden Ghost Crab (O. convexa) and the Kimberley Ghost Crab (O. fabricii). I realized that these two species are being confused on iNat with obs of both species being ID'd as O. convexa.

According to Sakai & Türkay, 2013:
O. convexa: Exorbital angles triangular and directed anteriorly.
O. fabricii: Exorbital angles acutely triangular and protruding outward.

I've annotated the images below with arrows pointing at the exorbital angles

Likewise in Sakai & Türkay, 2013 and Table 1 in Jones, 1988, The Occurrence of Ocypode pallidula Jacquinot (Decapoda, Brachyura) in Australia and the Coral Sea
O. convexa:
Ocular styles very short
Median notch of lower orbital deep
Pterygostomial region tuberculate all over its surface.

O. fabricii:
Ocular styles very short
Median notch of lower orbital slight
Pterygostomial region distinctly tuberculate except along lateral sides of buccal cavern.

I've annotated these 3 features in the images below

Its hard to find photos of live crabs in publications but I found 1 in each of Rae, 2018 and Piersma et al., 2016

These photos are consistent with O. fabricii being a more ochre colored, sharper/more angular crab with silver/pale blue eyes while O. convexa is a light yellow colored, rounder crab with jet black eyes.

Thanks to @luccio42, @dariodipas, @possumpete @keirmorse @johneichler and @viviroceania for making their awesome photos available for this post!

Publicado el 15 de enero de 2023 04:14 por loarie loarie | 4 comentarios | Deja un comentario

20 de enero de 2023

A new Computer Vision Model including 1,465 new taxa in 40 days

We released a new computer vision model today. It has 69,966 taxa, up from 68,853.

This new model (v1.6) was trained on data exported exported last month on December 11th and added 1,465 new taxa.

Taxa differences to previous model

The charts below summarize these 1,465 new taxa using the same groupings we described in past release posts.

By category, most of these 1,465 new taxa were insects and plants

Here are species level examples of new species added for each category:

Click on the links to see these taxa in the Explore page to see these samples rendered as species lists. Remember, to see if a particular species is included in the currently live computer vision model, you can look at the “About” section of its taxon page.

We couldn't do it without you

Thank you to everyone in the iNaturalist community who makes this work possible! Sometimes the computer vision suggestions feel like magic, but it’s truly not possible without people. None of this would work without the millions of people who have shared their observations and the knowledgeable experts who have added identifications.

In addition to adding observations and identifications, here are other ways you can help:

  • Share your Machine Learning knowledge: iNaturalist’s computer vision features wouldn’t be possible without learning from many colleagues in the machine learning community. If you have machine learning expertise, these are two great ways to help:
  • Participate in the annual iNaturalist challenges: Our collaborators Grant Van Horn and Oisin Mac Aodha continue to run machine learning challenges with iNaturalist data as part of the annual Computer Vision and Pattern Recognition conference. By participating you can help us all learn new techniques for improving these models.
  • Start building your own model with the iNaturalist data now: If you can’t wait for the next CVPR conference, thanks to the Amazon Open Data Program you can start downloading iNaturalist data to train your own models now. Please share with us what you’ve learned by contributing to iNaturalist on Github.
  • Donate to iNaturalist: For the rest of us, you can help by donating! Your donations help offset the substantial staff and infrastructure costs associated with training, evaluating, and deploying model updates. Thank you for your support!
Publicado el 20 de enero de 2023 18:59 por loarie loarie | 16 comentarios | Deja un comentario