How do you distinguish between Kelp Rockfish and Grass Rockfish.

I was browsing the leaderboard and fish pics of the DOTY comp (aka staring incessantly) and for the life of me I can't tell the difference between a Grass Rockfish and a Kelp Rockfish, I know gill rakes has something to do with it but are there any other subtle cues I'm missing?

NOAA has some info on the distinctions

http://www.afsc.noaa.gov/groundfish/RockfishGuide/Rockfish_Pages/Kelp_rockfish.htm

The answer that popped into my head instantly was:

"I'd ask Big Jim."   

Truth.   

According to the DFW dude that frequents SWS it's most easily done by looking for a black spot on the gill plates. The brown rf has the black spots while the kelpie doesn't. Other than that from my experience browns have color patterns more similar to blacks with large black squares above and below the lateral line while kelpies have a pattern more similar to blues with the checkerboarding.

A brown


A kelpie


Not the best photos but in real life the black spot is easily seen. Browns in SWS are VERY rare and I have only landed 3 and all were 20" class fish. In SC they are common and they are also fairly common in Monterey. Hope that helps.

Whoops kelpies and grassies LOL.

A grass rf


Grassies and kelpies are easily distinguished by their shape. Grass rf have a shape actually similar to cabezone with a short stout body and a huge head. They also tend to have a very pronounced white belly and their mouths are almost entirely white inside while a kepie's mouth will have a tinted brown appearance. Grass rf also have very fleshy mouths in comparison. 

very nice explanation Tim!

 Even more info.  Thought I was pretty good at IDing fish but with the Kelp vs Grass I was Wrong.... I had them backwards .   
 Big Jim and Fuzz set me straight
 Per Big Jim
"Internally...I checked the gill rakers (the white part not the red part) of a kelpie side by side with a grassy.  Real obvious. Kelpies are long, thin and delicate and grassys are short and stubby."  and he was Right 

Great question Chuck!!

I struggled a lot last year with this, and fuzz and Rick helped me get better at IDing the difference between the two.

Externally, like Meathunter said, the grassy's head is a a lot bigger and their body is stockier. The biggest external clues are the oversized fleshy pectoral fins of the grassy. The kelpies pecs are thinner and less fleshy.

Also...getting a grassy up to 18-19 inches is not that uncommon, but I don't think I have ever seen a kelpy much over 16 inches.

Also...you will often see kelpies suspended up in mid water column either out in the open or right around their kelp stalk....almost all grassy's I have seen have been chilling on bottom and/or tucked back in holes/cracks.

Now, like Desertdiver said, internally it is super easy to tell. Look at the gills. You can really tell the difference there.

Check out the attached little pic I took on my phone of the DFG Rockfish ID poster I have on my wall at work. It is really easy to see in real life as well!

Here are the kelpys entered into DOTY:

http://doty.ncka.org/speciesleaders/list_by_species/14

And the grassys:

http://doty.ncka.org/speciesleaders/list_by_species/13

Head size, pectoral fin shape/size and gill rakers...that should steer you in the right direction.

Check out the attached pic of fuzz's that really shows the size and meatiness of a grassy's pectoral fins!

Hope this helps!!

 

Sincerely,

Jim

Check this out Chuck....look at the difference in head size/shape and pectoral fin "fleshiness" between the smallest grassy in DOTY (mine, surprise surprise  ) and my biggest kelpy.

http://doty.ncka.org/catches/283

http://doty.ncka.org/catches/122

Obviously a DOTY pic won't show the gill rakers so fuzz, Rick and I look at the head shape/size and pectoral fins to ID the fish.

If we need more info I'll get those two guys to chime in cuz they have way more knowledge than I do.

 

 

Sincerely,

Jim

Wow, thanks for all the awesome input guys. Now when I get out this weekend I might actually have a clue about which fish in catching.

Wow, thanks for all the awesome input guys. Now when I get out this weekend I might actually have a clue about which fish in catching.

LOL!

No worries Chuck...that's one of the cool things about DOTY IMO is learning more about the different species etc.

 

 

Sincerely,

Jim

I like the I'd aspect of DOTY as well and I'm also getting pretty excited about hunting new species. That was only my second cabezon and now I'm hell bent on scoring a halibut with a polespear.

I like the I'd aspect of DOTY as well and I'm also getting pretty excited about hunting new species. That was only my second cabezon and now I'm hell bent on scoring a halibut with a polespear.

Awesome dude!!

You still need a monkeyface for DOTY as well! Depending on how surgy/rough the shallows are we can hopefully find you one on Saturday! 

I also need a halibut, I'm like 0 for 20 looking for them the past three years  ....let's hook up and go try and find one!! 

 

Sincerely,

Jim

A monkey face would be awesome, I've never even seen one while diving. I'm trying to rig up a wrist strap for my flashlight so it's nearby and convenient when I approach a good hole. I'm excited to hook up this weekend dude. And yeah freediving halibut hookups would be awesome.

A monkey face would be awesome, I've never even seen one while diving. I'm trying to rig up a wrist strap for my flashlight so it's nearby and convenient when I approach a good hole. I'm excited to hook up this weekend dude. And yeah freediving halibut hookups would be awesome.

I know some good spots if the swell is not too big...this one spot I have in mind is easy to find, but has to be calm...the other is trickier to find but is super cool and worth looking for. 

Desertdiver needs one too. We can all go monkey hunting!

Can also show you guys how I skin them and tell you how to make the bomb ceviche out of the boogers.

 

 

Sincerely,

Jim