Tuesday 16 August 2016

Hunting for worms in Adelaide


A few weeks ago, I went hunting for worms. Funky worms. Gorgocephalids, in fact – pronounced gor-go-kefalids, they're a family of digenean trematodes that parasitise Kyphosid fishes. Or, in layman's terms, medusa-headed parasites that live in the guts of drummers.

Some gorgocephalids. Note the "gorgon"-like oral suckers - it's ok though, they don't have eyes so they can't turn you to stone! Image credit: Bray & Cribb 2005 (A & B), Manter 1967 (C), Yamaguti 1971 (D).

Clearly, these little guys are pretty damn different to anything that I work on. But sometimes it's fun to learn about something totally different, because science is cool, and nature is awesome, regardless of what exact aspect you study.

A pied cormorant chilling at West Beach Boat Ramp.

I tagged along with a couple of fellas from the Cribb marine parasitology lab, Dan Huston and Storm Martin, on a specimen collecting trip to Adelaide. Dan was on the hunt for the type specimen of a gorgocephalid species he's describing for his PhD. This meant travelling down to Port Noarlunga (where the first species in the family was described) and fishing for silver drummer. The boys did a lot of spearfishing, while I kept an eye on them from the shore and made sure they weren't in any trouble (i.e. weren't getting investigated by great whites or smashed against any rocks).

Dan and Storm getting in to spearfish at Gull Rock, with some ominous weather as a backdrop.

Unfortunately, our timing was pretty bad – as soon as we arrived down south, Adelaide experienced its wettest July day in 75 years, also enduring some insane storms and a pretty unfortunate cold snap. Even though the guys braved the water whenever the weather was calm enough to be safe, all the fish seemed to have evacuated. But despite our non-existent sampling success, the guys made some great contacts down at SARDI, and their generous help should assist with getting the samples they need.

A few different echinoderms from the shore at Blanche Point.

The Cribb lab work on discovering and describing new species of trematodes, as well as figuring out how they all fit together on the evolutionary tree. Just this week, Dan had a paper describing the complete lifecycle of Gorgocephalus yaaji come out in the scientific journal Systematic Parasitology. Though we've known about this species since 2005, up until now nobody knew exactly where it lived most of its life - only that it ended up in the guts of a species of drummer (Kyphosus cinerascens). Now we know that it starts off its life in a species of marine snail (Echinolittorina austrotrochoides), developing inside the snail's guts, then emerges and hangs out on algae until it gets eaten by the herbivorous drummer, in who's digestive tract it will reproduce sexually and eventually die. Crazy, complicated stuff – and that's just a simplified version of events!

Dan and Storm looking for parasites in a Western Australian Salmon.

This kind of work is not only cool, but it's also very important – the field of taxonomy can be somewhat marginalised in today's scientific world, but the truth is, there are estimated to be more species alive right now that we don't know about than the ones that we do. Every day, species go extinct that we didn't even know were there. And if we don't even know they exist, imagine all the things about them that we don't know! Not only is this frustrating (yet also kind of wondrous) news for those of us obsessed with the natural world and the creatures that live in it – but the rest of scientific research depends on knowing what species it is we're looking at. It's definitely not a good thing if you've accidentally collected a bunch of cryptic species but are treating them all as the same thing in your results.

Various sea critters I found along the way.

I'm looking forward to hearing more about the guys' discoveries – and maybe one day I'll save up enough to tag along on one of their more exotic field trips to the Great Barrier Reef (but I doubt it!).

Just looking for fish (at O'Sullivan Boat Ramp).
All images by Rebecca Wheatley unless otherwise credited.