thebeachcomber's Journal

As I write more journal posts, it becomes more annoying for me to retrieve old ones due to the current journal interface on iNat. So I'm making this post as an index for all of them, and will add to it as I write new posts. A link to this index will be on my profile.

May 2021 - Seashell field guide finally out!

November 2021 - Get on board the new Xmas beetle project

February 2022 - Big Bushfire BioBlitz

April 2022 - Commonly confused pairs of Australian arthropods

April 2022 - Setting up projects with 'Australia' as a place filter

May 2022 - Australian moths and the influence of Victor Fazio III

December 2022 - Duck River Survey finished

February 2023 - Xerochrysum cleanup

February 2023 - Australian Agaristinae

February 2023 - Barrage of notifications - an apology

April 2023 - Australian Bidens cleanup

June 2023 - Splitting of Lysimachia arvensis colour morphs

July 2023 - Guide to non-yellow flowering Oxalis in Australia

August 2023 - Norfolk Island vascular plant curation

October 2023 - Gazania in Australia

October 2023 - Check old Ericaceae observations

November 2023 - 2023 bird taxonomy changes - an Australian perspective

November 2023 - Deobscuring Tasmanian species

December 2023 - Hedera in Australia

December 2023 - Deobscuring Australian species (IUCN statuses)

February 2024 - Identification of Actinodium

February 2024 - New Western Australian Isopogon changes

April 2024 - Major changes to Leptospermeae

May 2024 - Diopatra along the eastern Australian coast

August 2024 - Eurybrachidae (especially the genus Platybrachys) identification in Australia

Anyone who has beachcombed along the eastern Australian coast at least a few times will likely have stumbled upon a Diopatra tube at some point. The inner lining of this tube is made of a tough, parchment-like layer, and isn't too exciting looking:

The outer layer, however, is much more unusual, with the worm attaching seaweed, shells and other debris to the tube:

At time of writing there are ~160 observations of Diopatra on iNat along the east Australian coast, from the Sunshine Coast down to the Victorian border. Most of these (~85%) are identified as Diopatra dentata, including many IDs by myself. At face value it seems like a straightforward one; a number of books and other marine ID resources, such as W.J Dakin's Australian Seashores and Graham Edgar's Australian Marine Life show images of these tubes and ID them as Diopatra dentata.

However, I recently discovered that this is not the only species found along the east coast, and there are in fact three described species in this region: amboinensis (at the northern end of the range), aciculata (along NSW) and dentata. Paxton's 1993 revision of the genus (see https://www.biodiversitylibrary.org/part/271283) provides descriptions for the tubes of each:

You'll notice that the descriptions are quite similar, and that, if dealing with an old and damaged tube with the outer layer partially or fully lost, as is often the case, it becomes very difficult to make an ID. So last night I emailed Pat Hutchings, an incredible polychaete expert and authority, about the situation. She confirmed to me that these Diopatra can realistically only be confidently IDed to species from the worms themselves, and that any records of just the tubes should ideally be kept at a genus ID.

Now based on collections and records referenced in the literature, dentata does indeed seem to be the most widespread and common of the three, and thus many of the records currently IDed as dentata on iNat are almost certainly correctly IDed. But because of the uncertainty, it's most appropriate to keep these IDs to genus, so I'm going to go through and bump them back now

tagging top IDers and observers:
@adrian2370 @nicklambert @twan3253 @urungaroger @ben_travaglini @leslieh @lynsh @cesdamess

feel free to tag others too