Diario del proyecto Australasian Fishes

Archivos de diario de julio 2023

20 de julio de 2023

Parasite on Seadragon

Karolyn Landat, @diverk (left image below), took this wonderful photo (above, left) of a Leafy Seadragon under a jetty in South Australia. Attached to the 'neck' of the fish is a parasitic isopod, Creniola laticauda.
Karolyn stated, "With regards to seeing the Leafy (or any critter underwater) with an isopod on it, you wonder how they feel with it stuck to them, especially when it's as big as that one! It must bother them surely. There is the urge to pick them off and relieve the fish of the burden, but of course we don't touch anything and it's obviously a natural occurrence (well, not man-made or induced at least), so you let it take its course and don't interfere. I've read somewhere that they do drop off eventually, which is reassuring. With regards to the dive in general, it's always a delight to see Leafies, we never got tired of seeing/watching and shooting them (with the camera). We hadn't seen a lot of them at that particular site/jetty, so it was a pleasure to find him.
Janine Baker, @marinejanine (right image above), is the founder and manager of the marine citizen science group South Australian Conservation Research Divers (SACReD), which has been active in South Australia for 15 years
Janine stated that "One of the seadragons I have identified in our Dragon Search SA project has been carrying the same female Creniola parasite for at least 1 year, in the same position. For some other identified animals in our set, the parasite is present at one time and then gone a few months later. One diver has observed several large female Creniola clustered at the head end on one seadragon, and that is uncommon. When there are multiple Creniola on a single animal, usually one large female is attached, plus some small males (which reportedly move from host to host)."
Janine sent the list, below, of links to seadragon records from South Australia that contain images of Creniola laticauda.
https://www.inaturalist.org/observations/147821507 - This observation shows a seadragon which has had a Creniola in same position for 12 months.
Thank you Karolyn and Janine for your observations and comments.
Publicado el julio 20, 2023 02:48 MAÑANA por markmcg markmcg | 0 comentarios | Deja un comentario

27 de julio de 2023

Bicolour Goatfish photographed well south of its 'official range'

Bill Barker (@billspud) informed me that "Transport NSW is going to replace the Narooma Wharf in the Wagonga Inlet sometime this year or next and it is anticipated there will be serious negative impacts on the marine life of the area, at least in the short term. Local conservationists are concerned that the work and the design should minimise the harm and facilitate the quickest possible return to its present richness."
He further stated that, "In order to establish a baseline and to underscore the environmental value of the wharf and its surroundings, divers and snorkelers from the Nature Coast Marine Group, a local conservation organisation, have carried out a series of surveys, which have so far recorded the presence of more than 200 marine species, of which around 100 are fishes, including many tropicals. The results are recorded on NatureMapr."
One tropical fish that caught Bill's attention was a Bicolour Goatfish, Parupeneus barberinoides. Andrew Green, (@dentrock), brought the observation to my attention, pointing out that the fish seemed well south of its recognised range. He was correct. The 'official' southerly distribution of the species is to Sydney, approximately 280 km to the north (view the Australian Faunal Directory species page).
Thank you Bill for uploading this interesting observation. Good luck with your surveys. Baseline surveys are essential for documenting the impacts of human activities on marine ecosystems.
Incidentally, you may want to contact Amanda Hay (@amandahay), the manager of the Australian Museum's Ichthyology Collection. You could ask her for a list of fish that have been collected in the area. I don't know if the collection contains specimens from the region, but it's worth asking. The list may contain historic records that could be of interest.
Publicado el julio 27, 2023 02:25 MAÑANA por markmcg markmcg | 1 comentario | Deja un comentario