Gobies and Blennies: What are the differences?

[Peace River]

Gobies and blennies are a common marine fish that aren’t always understood or appreciated. They have unique and sometimes quirky behaviors that can make them interesting to watch, but sometimes it takes patience. What is your experience with gobies and blennies? Are you familiar with their commonalities and their differences? Please take a look at the choices in today’s poll and let us know which options that you think are not true. Are there any other differences that you would like to highlight? Do you have any tips about how to tell the difference or how to care for these types of fish?

Yellow spotted goby; photo by @ebeez

 

[Jacked Reefer]

Dart gobies are definitley not benthic! they are free swimmers. So voting that one

 

[BuddyBonButt]

So.. yellow watchman gobies are 100% benthic but midas blennys aren't always. Mostly see mine in the water column... so if we are lumping together.. then I guess they "aren't" bottom dwellers???

 

[i cant think]

All are wrong!
It highly depends on the species;
Some have a split dorsal like the Clown Gobies or Two Spot Blennies.
Only a few Blennies will change colour depending on surroundings, most noteably the Lineatus and Midas Blennies do this. Others change due to stress and I don’t find that to be a true ‘colour’ change.
I believe only two species of Goby will actually use their Pectoral fins to walk; The infamous Discordipinna griessingeri and Discordipinna filamentosus use them.
Gobies nor Blennies are totally Bottom Dwelling fish, they’re all some sort of rock dweller however they are not all bottom dwellers as seen in species in the Meiacanthus and Gobiodon genera.
And finally;
Blennies and Gobies do not live in reefs! Most of them actually live on the similar places as to where wrasses live;
Seagrass beds and small places with just rubble!

Gobies are one genus I’ve really studied in my time in fish keeping, they’re a fascinating family. And when you say tell the difference what do you mean?
As in how easy they are or how to ID different species? IDing different species is an entire other topic that is incredibly hard to go in depth in however identifying Goby from Blenny is rather more easy - Blennies are generally more ‘boxy’ and have quite distinct patterning and body shapes compared to Gobies.

 

[Slocke]

4 yes or no questions where all the answers are sometimes

So rather pointlessly argue over it how about a fun video of my weird goby:

 

[i cant think]

4 yes or no questions where all the answers are sometimes

So, in reality all 4 are no;
Sometimes is more of a no to these questions - I know there are some questions when you answer ‘Sometimes’ and it leans closer to the yes side however this is almost definitely 4 statements that lean to the No side more than anything.

 

[Cthulukelele]

Yeah it's such a challenge if you were to compare different individuals from the groups, midasblennies and fang blennies are much more similar seeming to dartfish than say a diamond goby. A perching blenny and a clown goby feel a lot more similar than a dartfish and a clown goby. The variability internally in the groupings is gigantic!

 

[Blue Spot Octopus]

One of my favorite fish, with his little buddy the true perc.

 

[KrisReef]

All are wrong!
It highly depends on the species;
Some have a split dorsal like the Clown Gobies or Two Spot Blennies.
Only a few Blennies will change colour depending on surroundings, most noteably the Lineatus and Midas Blennies do this. Others change due to stress and I don’t find that to be a true ‘colour’ change.
I believe only two species of Goby will actually use their Pectoral fins to walk; The infamous Discordipinna griessingeri and Discordipinna filamentosus use them.
Gobies nor Blennies are totally Bottom Dwelling fish, they’re all some sort of rock dweller however they are not all bottom dwellers as seen in species in the Meiacanthus and Gobiodon genera.
And finally;
Blennies and Gobies do not live in reefs! Most of them actually live on the similar places as to where wrasses live;
Seagrass beds and small places with just rubble!

Gobies are one genus I’ve really studied in my time in fish keeping, they’re a fascinating family. And when you say tell the difference what do you mean?
As in how easy they are or how to ID different species? IDing different species is an entire other topic that is incredibly hard to go in depth in however identifying Goby from Blenny is rather more easy - Blennies are generally more ‘boxy’ and have quite distinct patterning and body shapes compared to Gobies.

The only thing I can add is that neither blennys or gobies are pipefish nor seahorses, but they all like live food and plenty of natural cover! Good complete answer @i cant think , A+

 

[Mr Fishface]

This was a thinker! I only knew a couple of answers as being wrong because of my experience with my own goby. But a couple I did not know about like if they live in reefs! These are the questions I love because there is always more to learn about this hobby

 

[Bruce Burnett]

Depends on species in each they are all not completely true as a group. So without looking it up not sure how to tell them apart. Not all goby are sand shifting.

 

[Slocke]

So, in reality all 4 are no;
Sometimes is more of a no to these questions - I know there are some questions when you answer ‘Sometimes’ and it leans closer to the yes side however this is almost definitely 4 statements that lean to the No side more than anything.

If the answers where definitive. "Gobies and blennies live in coral reefs" for example is a "may". If it said "all gobies and blennies live in coral reefs" then that would be "not true" but since some gobies and blennies live in coral reefs the statement is neither "true" nor "not true" just ambiguous nonsense.

Here's funner question. Are these true gobies or true blennies from the family Gobiidae or Blenniidae?

A) Engineer goby


B) Ribbon goby


C) Bearded worm goby: (not my photo)

D)Orange Toadfish: (not my photo)

E)Sabretooth Blenny: (not my photo)

 

[i cant think]

If the answers where definitive. "Gobies and blennies live in coral reefs" for example is a "may". If it said "all gobies and blennies live in coral reefs" then that would be "not true" but since some gobies and blennies live in coral reefs the statement is neither "true" nor "not true" just ambiguous nonsense.

Here's funner question. Are these true gobies or true blennies from the family Gobiidae or Blenniidae?

A) Engineer goby


B) Ribbon goby


C) Bearded worm goby: (not my photo)

D)Orange Toadfish: (not my photo)

E)Sabretooth Blenny: (not my photo)

A is neither goby nor blenny and in fact has it’s own classification of Pholidichthyidae
B is a true goby, is was formerly known as a Microdesimidae (Dartfishes/Firefish) but is now in the Gobiidae family.
C is from the subfamily Amblyopinae (Commonly called Eel/Worm Gobies) and not a true goby
D is not a true Goby and the Toadfish are from several different genera I believe the orange is from the Opsanus genus. No Toadfish genus goes into the Gobiidae or Bleniidae
E is however a true Blennid of the Plagiotremus genus and are generally known as ‘False’ or ‘Mimic’ Blennies.

 

[HankstankXXL750]

So plenty already on here who say all are false or at least not absolute. So I’ll just add my 2 cents worth on keeping them.
I love the sand sifting gobies I have a diamond and a pink spotted 1 each on my reefs.
These following are mixed mixed between my tanks.
Bar gobies in the water column out and active a lot. Have a school of 6

Fire fish Gobies, water column but hide sleep in burrows under the rocks. Have two schools of 3 red and a school of 3 purple

Weaver goby, bottom dweller pairs with pistol shrimp neat but hardly ever see. Thought was dead then saw it a week ago

Yellow Watchman Goby. Bottom dweller pairs with shrimp. Have tried to establish pairs in both of my reefs. Don’t believe I have been successful as I only see one at a time and at least one pair was rooming together in a single cave at one time.

Fang goby have a school of three. Live in the water column. Bite is supposed to be poisonous, but I don’t believe that dangerous for humans (unless highly allergic like bees can be) love the gold and black stripes. Also active and out alot

blue gudgeons not sure if gobies but shaped a lot like my bar gobies. Notorious hiders. Only come out to eat or if viewed from a distance. Get close to the tank and the dart under the rocks to their home. Mine are beautiful blue though.

Dragon Goby all over the tank and active swimmer see it a lot.

Lawnmower blennies love them great Algea eaters. I keep one in ever tank I believe they will be safe in. (Not with my puffers and groupers) perch in the rocks high or low and will constantly graze Algea from rocks or glass. Mouth marks on film Algea look like lipstick kiss marks.

Midas blenny love ours but changed from bright yellow to a brown with just small
Hints of yellow. Believe to resemble our bi-color blenny. Love both of these especially how the back into holes in the rock. No man on earth can back into a parking space as quick and clean as these guys. Then they leak out at you. Just a note. The bicolor doesn’t stay the pronounced brown front orange back half as they mature the orange recedes to just a little around the tail.

Tail spot goby super cute really small and also has great back it into a hole skills.

Red Scooter Blenny way different in appearance than my other gobies and think he is probably technically a dragonet as these to follow. Bottom dweller super cool to watch him “scoot” along the bottom. Chose the red, but the browns are just as cool. Along with my next group, these require a pod population to thrive.

Psychedelic Green Mandarin Goby, Target (circles) Green Mandarin Goby, and Ruby Red Dragonet.

MUST MUST MUST HAVE POD POPULATION BEFORE ADDING THESE TO YOUR TANKS.

Super cool and awesome fish, Psychedelic Green the reason I got into saltwater. Can’t do those colors in freshwater. I have one of each of the mandarins and several of the Ruby reds (Nebraska Cornhusker Red, my wife insisted).
All of them eat frozen, and I watch them do it, but I purchased pods frequently when I introduced them, and although I don’t sit at my tank at night to see if I have any, the amount of amphipods I encounter when fragging or maintenance (and how fat and plump) all of them are I’m sure there is a plentiful amount. THIS TO BACK STOP MY STATEMENT THAT MINE EAT FROZEN. I’m not saying you can’t keep them alive with frozen, but I have seen many perish weeks after someone got them and they are wondering what went wrong (saying I didn’t see ich or anything) but they don’t tell you if it was fat and happy. Please please only add these to pod established tanks or tanks your willing to dose pods to regularly.

That might be all on mine, since I can’t find the Salinity tester, food tweezers, or anything else I used 5 minutes ago, I may have missed a couple.

 

[Slocke]

A is neither goby nor blenny and in fact has it’s own classification of Pholidichthyidae
B is a true goby, is was formerly known as a Microdesimidae (Dartfishes/Firefish) but is now in the Gobiidae family.
C is from the subfamily Amblyopinae (Commonly called Eel/Worm Gobies) and not a true goby
D is not a true Goby and the Toadfish are from several different genera I believe the orange is from the Opsanus genus. No Toadfish genus goes into the Gobiidae or Bleniidae
E is however a true Blennid of the Plagiotremus genus and are generally known as ‘False’ or ‘Mimic’ Blennies.

Uggh! Right as always.

Though why the false or mimic blenny would be called a false or mimic blenny when it is a tru blenny that mimics cleaner wrasse... It is too bad they are absolute demons and cannot be kept in our tanks. For those that don't know they pretend to be cleaner wrasse then bite chunks out of their unsuspecting victims.

 

[addictedtoreefing]

One of my favorite fish, with his little buddy the true perc.

is it a midad?

 

[addictedtoreefing]

I just got my first two a midas and supposedly a bicolor though he is solid blue. I really like their personality. in quarantine now.

 

[design.maddie]

I have three blennies in my tank, one doesn't have a continuous dorsal and another isn't a bottom dweller. The other has pectoral fins for walking.

 

[steveschuerger]

Well I have 1 blenny and no gobies at present. He doesn’t care what people call him .

 

[i cant think]

Uggh! Right as always.

Though why the false or mimic blenny would be called a false or mimic blenny when it is a tru blenny that mimics cleaner wrasse... It is too bad they are absolute demons and cannot be kept in our tanks. For those that don't know they pretend to be cleaner wrasse then bite chunks out of their unsuspecting victims.

I mean, you could keep a mimic blenny in your reef however if you did it would have to be a species only with a few sacrifices every now and then…

As for being right, you’re challenging me on my second most researched family! I love the Gobies - my first article was on these guys