Which type of watchman goby?

[Katrina71]

Btw, she is the most aggressive fish in his tank! She even goes after a blue velvet damsel. Don't be surprised if your fish is not timid.

 

[John A!10]

My son's is all white. Spots are now very blue.

Doesn’t look like that at all!

 

[John A!10]

Also got this pic.

 

[Katrina71]

It looks like a juvenile blue spot to me

 

[John A!10]

It looks like a juvenile blue spot to me

I think it is because mine has some little blue stripes which I think will turn into those darker blue ones does your sons sift the sand, and or keep the sand bed clean

 

[Katrina71]

I think it is because mine has some little blue stripes which I think will turn into those darker blue ones does your sons sift the sand, and or keep the sand bed clean

Yes! Really well. Warning if you put little brittle stars in, put them on the rock...if you drop them in...bye bye. Whole.

 

[John A!10]

Yes! Really well. Warning if you put little brittle stars in, put them on the rock...if you drop them in...bye bye. Whole.

Thanks I’ll also look for a tiger pistol will it keep the sand bed clean, rearrange it, also is she active?

 

[Katrina71]

Thanks I’ll also look for a tiger pistol will it keep the sand bed clean, rearrange it, also is she active?

Neither ever hide. They are constantly working.

 

[John A!10]

Will it pair up with the red banded snapping shrimp as I want a little more color. Is your tiger pistol colorful?

 

[vetteguy53081]

Yellow watchman.

 

[John A!10]

Yes! Really well. Warning if you put little brittle stars in, put them on the rock...if you drop them in...bye bye. Whole.

Didn’t get it so they sift sand or keep the sand bed clean, or both.

 

[Nick30G]

I think its a yellow watchman. Sometimes yellow watchmans will change their color almost when they are stressed or as they age they can change colors from juvenile to adult.

 

[Bob Escher]

I have one of him and a Diamond Watchman. He is not a diamonth watchman.
A Diamond watchman also sifts sand and cleans sand he does not. I love both of them by the way.

 

[CMG]

Also got this pic.

Looks exactly like mine that was sold to me online as a YWG but after seeing one at the store yesterday I’m not so sure. Mine is 3-4x the size of the one I saw. I know this is 2 years old but wondering what yours looks like now if it’s still around

 

[Isosceles]

Also got this pic.

I'm very late but this looks like the lagoon watchman goby (Cryptocentrus cyanotaenia) to me. Note diagonal stripes on the gill plate. C. cinctus does not have this.

There's only really 5 true "watchman" gobies that come into the aquarium trade, out of the 41 accepted species. True watchman gobies are from the genus Cryptocentrus. Diamond gobies and the like are from the genus Valenciennea (sleeper gobies).

The watchman gobies that come in (in order of most to least common) are:
C. cinctus (yellow watchman goby)
C. melanopus (pink watchman goby)
C. pavoninoides (blue spotted watchman goby)
C. cyanotaenia (lagoon watchman goby)
C. leptocephalus (pink spotted watchman goby)

C. cinctus is obviously the most common. They have that weird grey form that no one knows the cause of. Some say it's breeding/adult coloration, some say it's based on sex or locality, but then they can all still randomly indiscriminately change between colors, and I know it's not a maturity thing because I have a 4" yellow male that spawned with a 3.5" grey female.

C. melanopus is actually what you're getting most of the time when you buy "pink spotted watchman gobies". I assume this misidentification comes from the fact that melanopus used to be a synonym of leptocephalus before getting split off as its own species. The easy distinction is in the face pattern, melanopus has thick elongated pink spots on its face that angle up to the back of the head, whereas leptocephalus has actual tiny pink spots. Sometimes the face patterns can overlap a bit though, so the most definitive difference is the third bar on the body-- in leptocephalus it connects to the anal fin, whereas in melanopus it connects just before it.

leptocephalus vs. melanopus:

C. pavoninoides is the real "blue spotted watchman goby". Aka the peacock watchman goby because of the blue dots on the dorsal fin. They're pretty easy to distinguish, between the dots and the weird barring pattern (5-6th + 8-10th bars are thicker). They don't come in as often as the first two but they do still get imported pretty often. NYAquatics has one right now they're selling as Valenciennea sexguttata, on sale for $25.

C. cyanotaenia also doesn't come in as often but liveaquaria and quality marine carry them sometimes. LA sells them for $30. As mentioned before ID'd by the diagonal blue stripes (namesake, cyanotaenia means "blue stripes"), but these can also change between yellow and brown. Still pretty distinct, but the yellow coloration and blue patterning between these, C. cinctus, and C. pavo. definitely makes the misidentification somewhat understandable, especially given they all overlap in range around mainland Southeast Asia (mainly Gulf of Thailand).

True C. leptocephalus still does come in but at this point it's significantly less than the other four. My guess is they're collecting "pink spot watchman gobies" more in the western portion of the range, which is mostly inhabited by melanopus, whose range spans from Western Australia to Southern Japan (pretty much everywhere west of Papua). Populations in the northern portion of the range are described as C. singapurensis but I can't see any discernable difference between the two. C. singapurensis is furthermore often considered a synonym of leptocephalus, which considering the status of (and resemblance to) melanopus, is a bit dubious. Leptocephalus comparatively has a much smaller range, and is pretty much just found from Sulawesi to Fiji (as the crow flies), however they do overlap with Melanopus between Sulawesi and West Papua.