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Glasseye Snapper

Member Since 11 Oct 2005
Offline Last Active Yesterday, 04:48 PM

Posts I've Made

In Topic: 3 Damsels and 1 I don't have a clue

06 October 2015 - 04:25 PM

Things are even a bit more complex. Using DNA sequences it became clear that the species D. albisella from Hawaii, D. strasburgi in the Marquesas match the DNA evidence. D. trimaculatus from the Red Sea and Zanzibar, and presumably the entire (Western) Indian Ocean , forms a distinct clade, more different than the Pacific D. trimaculatus is from the other three Eastern relatives. Some of the D. trimaculatus and D. auripinnis from the Pacific mix together on the phylogenetic tree so they really are very similar despite the different colouration.


One of the phylogeny papers also stated "On the other hand, D. auripinnis coloration patterns (yellow lower body and fins) may either be reflective of recent speciation with little genetic divergence (or lineage sorting), or due to ecological adaptation to turbid waters (Randall & Allen 1977)." They don't explain the turbid waters logic but often fish have a light belly to stand out less against the bright surface when seen from below. If the turbid waters are yellowish then perhaps a yellow colouration of the lower body works better. However, I've never seen noticeable yellow water colouration near reefs except for algal blooms in the shallow lagoons behind a fringe reef. I don't find it very convincing but it is my best guess at this point.



In Topic: Unknown Fish from GBR Australia

05 October 2015 - 06:54 PM

Hi Craig,


BHB has been on my wishlist but more for a combination trip if I happened to be in the region. You just gave me another reason to find a way to make it happen. I'd also like to see the different fish along the US Eastern shores as I've only been further south in the Caribbean. I started diving at 18 in lakes and North Sea until graduate studies put it on pause for 13 years. Have been diving every year since but am too far from an ocean to make short trips.


Brian - thanks for your kind words and being a fellow slow-diver. I've been having a few select people check out the website and it is getting closer to being ready for adding more species. But I still need to occasionally make structural changes and that is easier with smaller numbers of dive sites and species. For instance on my private server the species pages now have their distribution plotted on a map and that should go live later this week. If you have any feedback on content or the site layout in general then send me a personal message via wetpixel and we can exchange email addresses.



In Topic: Sand Goby - Istigobius sp.

05 October 2015 - 06:17 PM

Hi Jim, great image again. It could be either I. goldmanni or I. spence. First one is supposed to be more greyish with many dark spots on nape, the second more brownish with fewer spots. But available images don't really match and as usual they are somewhat variable. Purely going by RFEI images I'm leaning towards I. spence but really it is a toss-up for me.



In Topic: 3 Damsels and 1 I don't have a clue

05 October 2015 - 05:42 PM

Hi Mark,


Thanks for chiming in and it seems you are right on the mark. I dug up the D. auripinnis species description paper (Randall & Randall, 2001). Until that time it was considered a colour form of D. trimaculatus but they now recognize 4 distinct but closely related species as a species complex: D. albisella from Hawaii, D. strasburgi in the Marquesas, D. auripinnis in the Line Islands, Phoenix Islands and Norther Cook's Islands. D. trimaculatus covers everywhere else all the way up to Africa and the Red Sea. They also mention that individuals from Fiji have partly yellow fins, as you pointed out, but apparently that is still considered a colour variant of D. trimaculatus.


Craig - when I get to making a species page for D. trimaculatus perhaps you can consider to donate the Fiji image so I can capture this colour variation with some of the details from the publication.



In Topic: Unknown Fish from GBR Australia

04 October 2015 - 05:31 PM

Seeing your typical highfin grouper in the second post having both the white saddles and yellow fin margin makes me more confident that the one in the first post is indeed a highfin grouper.


There are several reasons I "know this stuff". Most important is probably that I'm a self-identified fish geek and have been since early childhood. Another is Reef Fishes of the East Indies, a somewhat pricey but priceless three-volume set of books with virtually all known reef fish in the coral triangle and areas west up to and including the Andaman Islands of Thailand. I've also found it to be very accurate unlike many other ID books. Another good, though certainly not error-free or complete resource is fishbase.


Unfortunately I only get to make one dive trip per year, but if I go I tend to make a lot of "slow dives", preferably solo or, better, with a like-minded buddy rather than a group and dive master. On one occasion I made 50 dives on the same house reef in a 3 week trip. I love that because you get a lot of time to really look at all the fish, get a feeling for their behaviours, habitat preferences and subtle differences with time of day, mood, developmental stage, or just intrinsic variability. If you look at them in detail you also get a sense of what aspects tend to be conserved within species and which are variable. That even helps when identifying fish you have never seen before, such as the Pseudocoris yamashiroi.


Finally, I am working on a website to help myself and others in learning about identification, distribution, typical habitat and behaviour. That means I have spend a lot of time looking through all my images. The framework is almost finished and then I will start adding more species. You can have a sneak preview here




When it is ready for prime time I'll announce it here on wetpixel.