Hi Bert,

The larvae of the south-European moth “Horse-chestnut leaf miner” (Cameraria ohridella) cause significant damages on Chestnut trees in Central Europe and are therefore of interest among plant protection scientists. It is documented in the scientific literature that up to now a number of natural predators (birds, grasshoppers, ants, mites, beetles) have been observed and some dozens of indigenous parasites have been recorded, mostly ichneumon wasps (superfamily Chalcidoidea). Although this is not a marine group it may be of interest for you. Best regards, Otto.

Hi Otto,

Many thanks. That helps. I got similar suggestions from your colleague Erik van Nieukerken (Naturalis, Leiden). Leaf-mining moths could be a nice model group for this topic. Best wishes, Bert

Many exotic freshwater crayfish have invaded European waters, and there appears to be an exchange of hosts and  branchiobdellan (annelid) parasites / symbionts; native parasites move to exotic hosts and vice versa.

Dear Julian,

Many thanks. I did not think about that myself. I'll ask my crustacean colleague, Charles Fransen, if he knows more about this. We have had several visitors over the last few years to study freshwater crayfish in the collection of Naturalis Biodiversity Center in Leiden. best wishes, Bert

Thanks Bert. The obvious other crayfish parasite is the crayfish plague oomycete Aphanomyces astaci, many forms of which coexist with its north American hosts, but is almost invariably lethal to European and other crayfish. About five strains of A.astaci have been identified in Europe, with slightly different lethality. There is a lot of European work published in 'Freshwater Crayfish' and elsewhere; as I am not an expert on this, to single out one author would be unfair to the rest! Best wishes, Julian

Hi Bert,

I have no examples of commensal or parasitic species, but there are native predators on introduced species. Examples are the native slug Goniodoris castanea on the ascidian Botrylloides violaceus (it even gets an unusual colour by this diet shift) and the slug Lamellaria perspicua on the introduced ascidian Didemnum vexillum.

Best wishes,

Marco

Thank you, Marco. That is also a useful reply. I'll try to find relevant publications. Best wishes, Bert

Hi Bert. There is a recent paper of an invasive pea crab living in new hosts in the coast of Spain. The paper is is Afropinnotheres by the research group of Jose Cuesta. Published in MEPS. Let me know if this is not enough info for you to find the paper and I send you a complete citation. Regards, Antonio

Hi Antonio. Thank you. This is probably the paper that you are reffering to, but the three host species of this aline crab seem to be indigenous: Drake P, Marco-Herrero E, Subida MD, Arias AM, Cuesta JA (2014) Host use pattern of the pea crab Afropinnotheres monodi: potential effects on its reproductive success and geographical expansion. Mar Ecol Prog Ser 498:203-215. 

Dear André, Thanks for your paper. Nice. It reminds me of Hydractinia. I am interested in papers on coralliths, rhodoliths, balanuliths and bryoliths. I have a copy of your 2014 paper. Best wishes, Bert

Two post-mortem examples from the Netherlands: in the Eastern Scheldt, empty shells of Crassostrea gigas offer a favourable habitat for the autochthonous crab Pilumnus hirtellus. In the coastal zone of the North Sea, empty shells of Ensis directus, emerging from the seabed, offer suitable substrate for egg deposition by native Nassarius reticulatus. For the last phenomenon see Het Zeepaard 67(6): 184-189 (this also refers to Cadée 2006 on balanoliths).

Thank you, Godfried. I'll look it up. I suppose that empty shells of Ostrea edulis and those of native Ensis species has similar functions in the past. Best wishes, Bert

Hi Bert

Ostrea edulis is much more flat so I suppose it offers less space compared to Crassostrea.

I do not know of other Ensis species with Nassarius eggs. Native Ensis magnus may offer a similar substrate but it has never been as abundant as Ensis directus nowadays. Nassarius reticulatus has strongly increased in the Dutch part of the North Sea after 2001. This is probably related to the availability of Ensis directus since the eightees, but climate change may have played a role as well.

I recently found out that the larval stage of Edwardsiella lineata is parasitic within the non-indigenous yellyfish Mnemiopsis leyidi. However, I'm not sure if E.lineata is indigenous or not. According to the attached paper it is most likely also non-indigenous.

And the thing with the Branchiobellids on cray-fish is probably the same. Introduced crayfish from North America introduces non-indigenous branchiobdellids as we do not have or hardly have any indigenous Branchiobdellids in The Netherlands anymore.

Article Parasitic anemone infects the invasive ctenophore Mnemiopsis...

Dear Bert, for parasites contact [email protected] our parasite specialist. he and students work i.a. on exotic species and parasites.

I myself wrote a paper in De Levende Natuur on positiver effects of Crassostrea gigas in Dutch water (If you can't beat them join them) many species do find shelter between Pacific oysters (paper in Dutch attached).

My paper on 'balanuliths' deals with dying E. directus. They emerge half above the sediment and can be used as a substrate for in particular balanids. In shallowwer water they are eaten by in partticular herring gulls that have learned to dive for them,papers attached

Gerhard C. Cadee

Examples of predation by crabs and fish in the Netherlands on the invasive crab Hemigrapsus takanoi in Nijland & Ates 2012: Het Zeepaard 72 (5/6) 123-125. 

By Thieltges et al: on the dilution of mussels parasites by the presence of the invaders Crassostrea and Crepidula.

Article Invaders interfere with native parasite–host interactions

Dear Godfried, Many thanks for both new tips. This reminds me that I wrote a paper myself on Crepidula and Crassostrea in the Netherlands being infested by Cliona celeta amd Polydora spp., although the focus of this paper was mostly on Ostrea shells and lime stone.

Hoeksema, B.W. (1983) Excavation patterns and spiculae dimensions of the boring sponge Cliona celata from the SW Netherlands. Senckenbergiana Maritima 15: 55-85.