#bioblitz

I urge everybody take part in this! Next weekend, April 25-28, get outside and take photos of whatever organisms you can find. It is mostly a friendly competition among the world’s cities, but there is a category for everyone else too. I especially want to encourage those of you who live in Philadelphia, or in one of the counties that shares a border with Philadelphia. Let’s beat last year’s numbers for species and participants. After you take the photos you’ll have another few days to upload them to iNaturalist.

Look at those peets, Lookit them.

As it happens, less than an hour before I took these photos, somebody at the Bioblitz asked me where they could find Velvet Worms, and I had to tell 'somewhere less dry than Julimar', which I felt was good advice - even with the rain that weekend, nearly every inch of ground was bare gravel, with the exception of the small piles of bark litter around the bases of the Wandoo eucalypts. Hardly good habitat for a Phylum that can dry out easily.

And then @purrdence was poking around one of those bark piles and found this.

Occiperipatoides gilesii also comes in blue-black, is found on the Swan Coastal Plain and adjacent areas on the Darling Escarpment, and is one of four species of velvet worm found in this corner of the country. Three of those used be considered one species -  Occiperipatoides occidentalis - but are now considered their own genus, Kumbadjena. Kumbadjena is derived from Noongar (or Nyungar) words referring to the southwest region of Western Australia where these are found. Occiperipatoides means 'Western-Peripatus-like'. Peripatus itself is the quitessential velvet worm, and means 'walking about'. Which they do. On adorable peets.

Like other Velvet Worms, Occiperipatoides is a predator, hunting down other invertebrates with its sensory tentacles, and immobilising them with glue sprayed from nozzles in their face. The glue glands are large, running half the length of the body, but it can still take several weeks to refill them. The prey is then devoured with curved jaws deep in oral cavity. Some velvet worm species are social, and hunt as a pack, with dominant females getting to feed first.

Reproductive anatomy and behaviour is complex. Some have bladed structures - on the face, again - that they appear to use to place sperm packets in the female's genital slit she she holds him in place, and others deposit semen on her skin. Immune cells in her blood then gather underneath the sperm packet, and dissolve the skin and spermatophore integument between them and the sperm cells, whereupon the sperm swims into her body and starts looking for the eggs. Some velvet worms give birth to live young (a few even have a placenta!), and some are known to stand gaurd over their offspring.

Predators of velvet worms include other invertebrate predators, birds, and Hemprich's coral snake Micrurus hemprichii of South America, which apparently has velvet worms as a major part of its diet.

Being soft-bodied, velvet worms rarely fossilised well, but it seems they are descendents of the marine Lobopods, such as Aysheaia and the famous Hallucigenia of the Cambrian-age Burgess Shale. It's unclear when they moved onto the land, but it was most likely during the Ordovician or Silurian.

Bug of the Day

The City Nature Challenge of 2025 is just over a week away! It's a citizien science project, in which you can help researchers understand what biodiversity lives in towns and cities, by documenting what wildlife there is around you.

It will take place April 25-29, and everyone is encouraged to join! All you need is your phone!

Some cities organize events (list of participating cities), but you don't need to join any official event. You can be on your own, with your phone camera - snapping pictures on things that grow on your sidewalk, or that you notice on the way to work.

During April 25-26-27-28, you are encouraged to take pictures of as many species of living things that you can. No need to go anywhere fancy - in fact, researchers are interested in learning what lives around you, in the cities we inhabit. How many species can we find?

You can submit any species, as long as it's wild (plants grown on purpose and pets don't count) - plants, bugs, mammals, birds, algae, fungi, mold, what have you! EXCEPT dogs, cats, and people.

You can submit the images to iNaturalist, a lovely app (& website) that also helps you identify what you saw. If your city doesn't not have a specific event going on, you can join the Global Event on iNaturalist, and submit your photos there.

Ochre Sea Star (Pisaster ochraceus)

There's a Solstice Sea Star Search happening this month (December 1-31)! The goal is to find and document sea stars on the California Coast.

"Sea star wasting syndrome decimated sea star populations along the entire West Coast between 2013 and 2014, hitting sunflower sea stars (Pycnopodia helianthoides), giant pink sea stars (Pisaster brevispinus), and ochre sea stars (Pisaster ochraceus) particularly hard. Many species are still struggling to bounce back—and the sunflower star may even be considered locally extinct in some areas. We lack data on many sea star species and need your help to gather more information on where these species are found.

Because tides are at their lowest point in December and June due to the winter and summer solstices, it's the best time of year for California beachgoers to search for sea stars—and make a difference for the recovery of these important species."