As we sharing anecdotal information about wolffish, did you know why the spotted wolffish received the Latin name Anarhichas minor (Olafssen 1772)?

It's easy to think that "minor" means smaller, and that would really be a misnomer as we know that it's the larger of the two species, not smaller than the common wolffish Anarhichas lupus (Linnaeus 1758).

However, in this case "minor" in Latin means "latter" i.e. this was thewolffish species which was described and given a Latin name later than the other.

The guy who gave the spotted wolffish it's Latin name was the Icelandic naturalist Eggert Ólafsson. In true spirit of Linné, he published Reise igiennem Island (Travels in Iceland) in 1772 (same year as he named the spotted wolffish ;-), an account of the scientific and cultural survey he conducted between 1752 and 1757. The book remains a seminal work on Iceland and its people. He drowned in a tragic boating accident in 1768.

I'm pretty sure this is the offspring of the common wolffish (A. Lupus). They're beautiful by the way, take good care of them :-)

That was a quick response Atle and you're the right person to respond, thanks!  Surprisingly,  we found no good graphical description of the larval-juvenile stages of yhese two species. Any references we may have missed?  If it is indeed common wolffish (and I think you're right) I think we're seeing better growth rates than published earlier.

There is a rather old paper with identification key for juveniles of these two species in the Barents Sea (as far as i remember the first author is Baranenkova). I can send it later (now I am out of my institute), if you interested . But as far as i remember juveniles of both these two speceis have got stripe on body.

I haven't read the paper mentioned above, but would also like a copy if possible :-) I did a simple Google image search and The Canadian Register of Marine Species provides two excellent pictures of the respective species (about the same size as yours Bjørn) that I think confirms our suspicion. I've tried to attach them. There are some early works on growth in common wolffish by Pavlov, Moksness and McCarthy, but they never (to my knowledge) included a descriptive comparison between the two species. As for growth rates, I've always been a bit skeptical about the one comparison that was done (a Master thesis from Univ of Tromsoe) showing extreme differences betweeen the two species, although I still think the spotted wolffish is a faster grower. I'm looking forward to hear about your experiences with this batch Bjørn.

Thanks again Atle for finding the pictures in the Canadian registry. Yes, all fisheries data indicate that the spotted grows faster in the wild and also reaches larger body size, but as you, I'm very skeptical of the extreme differences in growth rate in the lab.

Wonderful pictures from the Canadian registry :-)

- and it really looks like it is the common wolffish that are growing in the experiment in Iceland. It is so exciting to follow these guys and see how they grow.

Just a minor note to add to the indication that the spotted wolffish grow to a larger size than the common wolffish. The Norwegian angling record for spotted (flekksteinbit) is 27.9 kg (also world record), while it is "only" 17.6 kg (a huge fish!) for common (gråsteinbit) - the world record for the common is 23.6 kg (Georges Bank, Massachusetts). Given the extensive sport fishing for common wolffish in Norway, the weights of the record fish should be close to the maximum size in the area. The list can be viewed here: http://www.klikk.no/produkthjemmesider/villmarksliv/de-offisielle-norske-sportsfiskerekordene-1452352.ece

Hi Joachim,  Thanks for these cool facts.

The largest spotted wolffish caught in Icelandic waters (in May 2003) was 144 cm and weighted 31 kg AFTER it was gutted! It was caught in a crayfish trawl at 200 m depth at 64°05’N, 14°21’W. Maybe a good fishing spot to recommend to your deep sea angling friends ;-)

As we sharing anecdotal information about wolffish, did you know why the spotted wolffish received the Latin name Anarhichas minor (Olafssen 1772)?

It's easy to think that "minor" means smaller, and that would really be a misnomer as we know that it's the larger of the two species, not smaller than the common wolffish Anarhichas lupus (Linnaeus 1758).

However, in this case "minor" in Latin means "latter" i.e. this was thewolffish species which was described and given a Latin name later than the other.

The guy who gave the spotted wolffish it's Latin name was the Icelandic naturalist Eggert Ólafsson. In true spirit of Linné, he published Reise igiennem Island (Travels in Iceland) in 1772 (same year as he named the spotted wolffish ;-), an account of the scientific and cultural survey he conducted between 1752 and 1757. The book remains a seminal work on Iceland and its people. He drowned in a tragic boating accident in 1768.

Hi all. Here is a picture of the Icelandic wolffish, taken today at 170 dph. The fish in the picture is about 25 g. It still has those broad stripes but it seems the spots are getting a little more prominent.

Is this from the same 

yes.

Sorry, something happened when I tried to answer from my phone yesterday, so the question was cut a bit short. Tomas understood what I meant :-) Well, I've completely changed my mind, and I'm also slightly embarassed, cause this is definitely A. minor. These are valuable fish. in my opinion. The broodstock currently available in Norway for the one active company (Aminor) consists of second (or third) generation cultured fish, and the risk of severe inbreeding is imminent. We're currently planning to fish wild specimens for a Research Project, and hopefully we'll get these fish in the next month or so (if the fishermen are succesful). As for the growth rates....this sudden species-transformation would explain the unusually fast growth observed :-)

Well, it is clearly difficult  to tell the species apart in the juvenile stage, so no need to feel embarrassed:)

Our fish never looked quite like the A.minor in the picture from the Canadian registry. They never had those large dots. So perhaps there are differences in juvenile appearances between stocks.  

Our fish started showing lots of small dots at about 120 dph. Recently the dots seem to be combining and forming a bit more irregular pattern.

Right now I'm not even sure the Canadian registry pics are correct :-)

It's weird, but spotted wolffish reared in captivity doesn't end up looking like wild spotted wolffish, even when they are the direct offspring from wild parents. I don't know the reason for this. It may be because of the formulated feed, the light conditions, tank environment or a combination of all these, but nevertheless they end up looking the same.....With several small dots instead of the leopard-pattern observed in the wild.

A closely related question is if there are any molecular methods already available to genotype these species.

For this, I placed a separate question on RG: https://www.researchgate.net/post/Is_it_possible_to_genotype_wolffish_species_to_see_if_fertilyzed_eggs_and_or_newly_hatched_larvae_belong_to_Anarhichas_lupus_or_A_minor

Atle. You make two interesting comments.

First, I agree with you that it's a relevant question if the Canadian pictures are correct - or at least if they are representative. At least, neither of them really fits the pictures we've taken (and posted here).

It's also very interesting to hear that the skin pattern of A minor is so much different in aquaculture than in the wild. A topic worth some research in itself! Perhaps we're already influencing the development of skin pattern early on. Our larvae are kept in while, plastic tanks with no bottom structures. Perhaps rocks, algae, hiding places etc are needed for the development of the "wild-type" pattern?

And Yes, I'm also coming around to the idea the we have A minor in our experiment, especially when I look at the row of distinct spots on the caudal fin

Picture taken yesterday c. 12 cm fish. I would rather say that it is A. minor than A. lupus, but I am not absolutely sure. I have been in many surveys where I have been measuring A. lupus at this sise and never been in doubt, however I think the small A. minor I have been measuring at surveys has been larger or about 20 cm, so I think that I have not been seeing so small A. minor before, as the fish is on the picture, so maybe it is a normal development of A. minor. However this raise some questions as could the environment influence the appearance ? Could it be a hybrid between A.lupus and A. minor?

The preserved A minor from the Univ Bergen collection looks actually quite similar to the A minor in the WoRMS photogallery, so they seem to have gotten it right. Do these have a row of spots on the caudal fin like our Icelandic specimens?

I dont think it's a hybrid. I was confused by the stripes on the younger fish posted first by Bjørn, but if you look at this pic with some of "my" fish, they're more or less the same, with some stripes still visible. As a sidenote, these fish are reared in a kind of basket, so excess feed and faeces are removed from the immediate proximity of the fish and can be flushed to create a good environment.

The photo you send us Atle is of A. Minor? If so I would say that the fish we have is A. lupus. The spot are more circular and isolated on the fish in the picture from Atle than on our fish. Further I don’t think they ever look like the juvenile on the picture that Þrándur just sent us.

Yes, it was A. minor. I think yours is too, but I've already changed my mind once, so who knows :-) You have to keep them alive now, if not for any other reason than to see which species you're ending up with in the end.

Same here about changed mind and I agreel about the importance to take good care of the fish to be later able to see which species it is with absolute certainity.

If you keep the fish a bit longer you will be able to confirm the species. I know that the coloration and patterns are confusing during first year of life. What about a biopsy to confirm species by genetics?

Hi Olov. We intend to do both; keep the fish for longer, and take tissue samples for genetic analysis. The question is how to genotype, and I'm placed this as a different discussion thread:

https://www.researchgate.net/post/Is_it_possible_to_genotype_wolffish_species_to_see_if_fertilyzed_eggs_and_or_newly_hatched_larvae_belong_to_Anarhichas_lupus_or_A_minor

If you have suggestions about how, who, etc, your comments are welcome

This is not my field of work, but for a person working in genetics it should be relatively straight forward by sampling a few cells, an egg or a larvae is more than enough. The DNA-id for wolf fish is probably available in open databases for comparison with your analysis. I can send you contact person for more information if needed

In my opinion is A. lupus

Hello everybody, I found a species identification guide (NAFO Wolffish Species Guide) and a wolffish identification guide by Fisheries and Oceans Canada (attached). The guide explains how the species can be identified on the basis of differences in the number and relative position of the vomerine teeth (the strong molars in the upper jaw). I took one dead fish and inspected the teeth and indeed, there were five sets of vomerine teeth just as described for spotted wolffish. There is, however, also a possibility that there may be some common wolffish in the group since the fish came from two separate egg clusters.

I am neither an expert on wolffish or a geneticist, but I can verify Olav G.'s remark that it doesn't take much tissue to run genetic analyses.  My agency's genetics laboratory has been quite successful working with the very small larvae of smelt that I have provided them.  They sequence the Cytochrome Oxidase subunit 1of the samples mitochondrial DNA (mtDNA CO1) as the means to identify the individual larvae as to their species.  I looked on the Barcode of Life (BOL) website, and did find various records of Anarhichas sp. from the North Atlantic region. I find the BOL database to be very helpful.  You can drill down to a specific species of fish and examine each individual fish's record (what fish collection holds the vouchered specimen, photos of the specimen, map location of where it came from, various details about the specimen, and if the specimen had a genetic sample it will give the genomic sequence).  Here is a link to a sample on their site that was a specimen of A. minor held in the fish collection at the University of Bergen.  Hope this is helpful. 

http://www.boldsystems.org/index.php/Public_RecordView?processid=DSFIB481-13

Sorry, I missed your comment about starting a different thread on the genotyping.

This pictures were taken yesterday, when we measures the juveniles of Anarhichas sp. According to the former picture the fish are not so different from the picture of A. minor juveniles from Atle Foss.  However in my opinion we still cannot be absolutely sure which species it is.