www.youtube.com/watch?v=GAxo...

Wikipedia: en.wikipedia.org/wiki/Drosoph...
The Berg Lab: depts.washington.edu/cberglab/wor...
Society for Mucosal Immunology: www.socmucimm.org/resources/ne...

Image credits:
Craig Biegler (www.inaturalist.org/observations...), CC-BY-NC
Jesse Rorabaugh (www.inaturalist.org/observations...), CC0

In 2001, a study comparing the genome of D. melanogaster and the human genome estimated that they share around 60% of their genes. Furthermore, about 75% of human disease genes have a match in this fly's genome, allowing it to be used as a model for human diseases such as Parkinson's and diabetes.

One of the most studied organisms in biological research, this fly is a very popular model organism due to several factors, such as inexpensive care, short reproduction time, and a well-understood lifecycle. It's so popular, in fact, that it was the first ever animal to be launched into space.

WoRMS: www.marinespecies.org/aphia.php?p=...
Habitas: www.habitas.org.uk/marinelife/s...
SeaLifeBase: www.sealifebase.se/Summary/Spec...

Image credits:
Christine Morrow (www.inaturalist.org/observations..., www.inaturalist.org/observations..., www.inaturalist.org/observations...), CC-BY-NC
Pierre Corbrion (www.inaturalist.org/observations...), CC-BY-NC-SA

H. dujardinii are usually found at depths of 0-50m (although greater depths, such as 80m or even as far as 300m, have been found), attached to stones, boulders, algae, empty shells of lamellibranchs, carapaces of crabs, at the base of gorgonians, and also on the ascidian Styela rustica.

Named for its gelatinous texture, this sponge contains no crystals or spicules (the hard, structural components that make up the skeletons of most sponges), making it aspiculous. Instead, it contains a network of fibrils that help to maintain its shape.

WoRMS: www.marinespecies.org/aphia.php?p=...
GBIF: www.gbif.org/species/2501...

Image credits to Robert P. Higgins from his book 'The Atlantic Barrier Reef Ecosystem at Carrie Bow Cay, Belize, II: Kinorhyncha', at www.biodiversitylibrary.org/page/41893415 (CC BY-NC-SA 3.0).

The discovery of P. praedictus led to Pycnophyes quadridentatus (of which one female was found) and P. flagellatus (of which one male was found) into one taxon, Paracentrophyes quadridentatus. This left only Pycnophyes echinoderoides as an aberrant species within Pycnophyes.

First discovered in 1983 by Robert P. Higgins, this species is notable in that various male juveniles were found to have penile spines, which were not normally seen until the final moult of the six juvenile stages. These juveniles were found to have longer lateral terminal spines than adult males.