Wednesday, January 25, 2006

Goddamn taxonomy

Well I have not posted in a while and so today I will post some complaints I have with the work I do... Now just to clarify, I like my job... And I understand the work we do is important, and I do not want to sell it short... But I do have serious issues about the way things get identified...

For example, Thor shrimp... My problem is this... Supposedly 2 species occur in the area, Thor manningi and Thor floridanus... The former has a rostrum that is armed but sometimes unarmed and has the 4th pair of walking legs it 3, sometimes 4 or 5, spines, not including the dactyl pair.... The latter is unarmed but can be armed, has 4 or 5 but sometimes 3 spines on the fourth walking leg... Honestly, wtf??? Both can look exactly identical, occur in the same areas and still be different... Who came up with this anyway??? Especially when carridean shrimp can be sexually dimorphic and we rarely, if ever, get gravid T floridanus... I just think its quite possible that they are the same species and want to know how people 100 years and 30 years ago came up with something otherwise...

Similarly Hippolyte shrimp that we get are very much the same... H zostericola and H pleuracanthus exhibit similar rostrums, however, the latter is supposedly much shorter (not extending beyond the antennule scale)... The problem I have with this is that we often get large batches of Hippolyte shrimp... And all the large ones are always H zostericola, and usually over 65% gravid, and all the supposed H pleuracanthus are small, juveniles and never, ever gravid... Again, many carridean shrimp are sexually dimorphic.... I just want to know where these people came up with the separate species (some literature suggests its a mistake that they should be considered the same species)...

And I don't even want to start on mud crabs, which a recent paper suggests through DNA sequencing that they aren't as many species or even genera as we are calling them...

I guess my big problem is that we are trying to identify things that we cannot identify, especially with none of us being carridean shrimp experts... And with all this information that perhaps they are the same that we still have to call them differently really bothers me... But oh well... I am just venting... Needed to post something, so this is it... Now you know a little more about what I do at work....

4 comments:

Tait said...

Yeah I remember reading a paper back in College that was saying how many species shouldn't even be identified beyond a Genus until Genetic sequencing techniques (which need to advance before we can do this) can verify their identity...I wonder if all these possible misidentified species stem from researchers wanted to be recongnized for discovering a new species...that is after all a great honor in the world of biology

john said...

yeah i mean i just really dont know how they come up with it... really... the second pleopod has a slightly concave shape... the lateral teeth are slightly more arcuate then straight... WHAT!!!! are you serious... for the mud crabs, the suggestion is that the person who is responsible for identifying them in the first place may have done so by color and patterns (ie spots) not taking into account the substrate or anything like that... and the goddamn shrimp f that... we have been saying all the time that we should only go to genus... if only you remembered what that paper was called, i would give it to my boss and be like, seriously, you dont want your work to be laughed at do you???

Tait said...

yeah I don't think I'm gonna remember where I read an article from like 5 years ago...but I do know your pain...when I had to sort samples at Moss Landing in Cali....sorting Amphipods was a big part of the deal..you wanna talk about very litte differnce between species..go look at amphipods....i swear to god they are all the same species

Adam said...

i definately feel your pain john. imagine not being able to physically handle the species you are trying to id. that is my biggest pain with my job. there are also some procedures that i don't agree with, like baiting the camera arrays and not taking that into account to do estimates of populations.