13 Cool Saltwater Aquarium Fish – #4 Will Shock you!

As saltwater fish keepers we have the privilege of keeping some of the most beautiful and amazing fish in our home aquariums. Cool saltwater fish from around the world with hundreds of amazing fish to choose from.

In this post, we have put together a list of 13 cool saltwater fish that you should consider keeping in your home aquarium if you want something special to wow your friends and family.

This list is in no particular order and was selected for various reasons, color, character, size, strangeness etc. To be honest we could have made a much longer list as there are so many wonderful and strange looking saltwater fish available to the home aquarists.

We simply selected the 13 most amazing fish we thought you’d like to see. I’m sure you’ll probably have added some others to this list if you were writing it, so please let us know what you would have included in this list. We’d love to hear from you

Let’s get stuck in and have a look at these amazing and cool saltwater fish.

13 Cool Saltwater Fish:

  1. Crosshatch Triggerfish (Xanthichthys mento)
  2. Dwarf Seahorse (Hippocampus zosterae)
  3. Cubicus Boxfish(Ostracion cubicus)
  4. Wartskin Angler(Antennarius maculatus)
  5. Tassle Filefish (Chaetodermis penicilligerus)
  6. Red Mandarin(Synchiropus cf. splendidus)
  7. Snowflake Eel(Echidna nebulosa)
  8. Volitan Lionfish
  9. Fiddler Stingray(Trygonorhina fasciata)
  10. Dragonface Pipefish
  11. Leaf Fish(Taenianotus triacanthus)
  12. Porcupine Puffer (Diodon holocanthus)
  13. Clown Triggerfish(Balistoides conspicillum)


#1 Crosshatch Triggerfish (Xanthichthys mento)

Also known as Blue Cheekline Triggerfish, this triggerfish has a very interesting pattern to its coloration making it one of the most desirable triggerfish for the home aquarium.

The face of this triggerfish has very distinct blue lines running from the mouth to the back of the gills. The fins of the Crosshatch Trigger are a stunning blue color with yellow borders, and the tail is red.

One of the most interesting facts about this fish is that it vocalizes using a “grunting” sound whether this is a form of communication or a warning to others is not known.

This fish can grow to approx 12″ in the home aquarium so a tank no less than 180-200 Gallons will be needed to ensure they thrive in your home aquarium.

These fish are very rare to see in the aquatic trade and as such fetch a high price tag of around $1200 each.

Scientific NameXanthichthys mento
Size11-12” Max
Family Balistidae
Care levelEasy
ColorsBlue, Red, Yellow, Hint of green.
Reef SafeWith Caution

dwarf seahorse

#2 Dwarf Seahorse ( Hippocampus Zosterae)

The Dwarf Seahorse (also known as the Seapony) is next level saltwater fishkeeping due to their challenging feeding habits. The constant need to feed them freshly-hatched baby brine shrimp, copepods, and other shrimp larvae make them difficult to keep in the home aquarium.

Their normal coloration is brown with spots but sometimes you can find a yellow specimen like the one in the picture making them very desirable.

Seahorses should be kept in a species-only aquarium in small groups of 4-6. You can also keep them with Pipefish and other small passive saltwater fish but you are limited on suitable tank mates.

A small 10-20 Gallon tank with living rocks and a small group of 4-6 seahorses looks amazing!

Scientific NameHippocampus zosterae
Care levelExpert Only
Reef Compatible No
Tank Size 10-20 Gallons
ColorsBlack, Tan, White, Yellow
Water ConditionsdKH 8-12, pH 8.1-8.4, sg 1.020-1.025,72-78° F,

yellow boxfish

#3 Yellow Boxfish ( Ostracion Cubicus )

The Cubicus is also known as Yellow Boxfish, Polka Dot Boxfish, or Cube Boxfish. Often Confused with the Longhorn Cowfish these amazing little fish are classed as expert level saltwater fish.

When young these fish have a bright yellow and spotty coloration like the one in the photo, but as this fish gets older they change to a more browner color.

The fish even though very small in size will chew and eat tubeworms and other invertebrates so if you’re thinking of adding these to a reef tank, proceed with caution.

Cubicus Boxfish can release a poisonous substance, called ostracitoxin when stressed from its mucous glands which will kill other fish in the tank very quickly. So choose your tankmates very carefully or this little innocent looking fish will have a surprise for any tank mate that shows aggression towards it. They have been known to wipe out a whole aquarium of fish!

Scientific NameOstracion cubicus
Family Ostraciidae
Size1.5-2” Max
Care LevelExpert Only
Reef SafeWith Caution
Water ConditionsdKH 8-12, pH 8.1-8.4, sg 1.020-1.025,72-78° F,
Venomous?When stressed

wartskin angler

#4 Wartskin Angler ( Antennarius Maculatus)

Wow! This fish is either really interesting or really ugly. Your call.

These little fish can be found perched on coral ledges in the Indo-West Pacific where they blend in nicely with the different corals. They come in various colors and are sometimes known as Warty Frogfish or Wartskin Frogfish. I think you can see where they get their name from.

The wartskin anglerfish has the chameleonic ability to change color which allows them to blend in with its surroundings. They are very peaceful fish but do need some extra attention with their diet making them a moderate level care fish.

You will need to feed this fish with feeder shrimp to entice them to eat when first introduced to their new home. Once acclimatized they will become easier to feed.

Most Anglerfish possess a specialized feeding device called an illicium, which is really a modified spine that hangs in front of their mouths. The illicium suspends a lure-like device called the esca in front of the anglerfish’s mouth, and when another fish takes the bait the anglerfish quickly grabs the pray and eats it.

Scientific NameAntennarius maculatus
OriginIndo-pacific,Indonesia, Vanuatu,
Size4-5” Max
Care LevelModerate due to feeding requirements.
Tank Size20+ Gallons
Water ConditionsdKH 8-12, pH 8.0-8.4, sg 1.020-1.024, 72-78° F,

tassle filefish

#5 Tassle Filefish ( Chaetodermis Penicilligerus)

This is one of the most amazing looking fish. This relative of the Triggerfish species is a master of disguise.

Often known as Leafy Filefish or Prickly Leatherjacket Filefish. The small terminal mouths of Tassle Filefish have specialized incisor teeth on the upper jaw; four on the inner jaw and six on the outer jaw.

The snout is tapered and projecting; eyes are located high on the head… Like the triggerfish, Tassle Filefish have small gill openings and greatly elongated pelvic bones creating a “dewlap” of skin running between the bone’s sharply keeled belly giving them a false sense of size and shape.

It has to be said that these fish are terrible swimmers. Often seen head down in the sand trying to find food and desperately trying to stay upright and stable in the current.

Filefish have an unusual scale morphology, in which setae (or spines) are present. These give the fishes skin a particularly rough texture, hence the name.

In my opinion, the Filefish family is one of the most underrated saltwater fish and you definitely need to take a closer look at this group of fish for your next purchase.

Scientific NameChaetodermis penicilligerus
Size 1-2"
Family Monacanthidae
Care Level
Water Conditions72-78° F, dKH 8-12, pH 8.1-8.3, sg 1.020-1.024


#6 Red Mandarin ( Synchiropus cf.Splendidus)

Part of the callionymidae or dragonet family these small but amazing fish will add color and character to any aquarium.

Word of warning: These fish are very difficult to feed and need a constant supply of copepods and other live foods when first introduced to their new home putting them into the expert fishkeeper category. Many fishkeepers do eventually get them to take dried brine shrimps and mysis shrimps but some don’t and they often waste away and die.

The red mandarin (Synchiropus cf. splendidus) is a variation of the striped or psychedelic mandarin fish (Synchiropus splendidus).

The head and body of the red mandarin dragonet are a fascinating and their stunning combination of blue, orange, and red. Male red dragonets may be distinguished from females by their extra-elongated first dorsal spine.

When seen close up you will realize how colourful and amazing they really are.

Scientific NameSynchiropus cf. splendidus
Familycallionymidae or dragonet family
Size3-4” Max
Care LevelExpert due to feeding requirements
Aggression levelPeaceful
Water Conditions
72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Tank Size30 Gallon
Reef CompatibleYes
OriginIndo-Pacific, Jakarta, Indian Ocean

snowflake eel

#7 Snowflake Eel (Echidna nebulosa)

This fish looks like it should be in a scary movie or in divers nightmares but believe it or not the Snowflake eel can be kept in aquariums with smaller fish as long as you keep them well fed and the fish are not bite size.

This species can change gender from female to male when a male is needed, a female changes sex and takes on the role.

Some Moray eels grow very large like the Indo-Pacific giant moray (Gymnothorax javanicus) which can reach almost 10 feet. However, the snowflake moray eel will grow to around 2-3 foot in length in a home aquarium making them perfect for saltwater tanks 50-60 Gallons+.

In the home aquarium, these fish will accept frozen foods like Shrimp, Mussels, fish flesh and will even take hand-fed foods ( Well use a stick) which is an amazing feeling once they are settled into their new home.

Two points to consider when thinking about keeping one of these amazing fish in your home aquarium. 1) They can escape and are often found dead on your living room floor. 2) They can disturb the rocks and substrate which can lead to rocks falling and killing either itself or other fish and even damaging the glass. Ensure all rock works are glued securely in place.

Scientific NameEchidna nebulosa
Care LevelEasy
Color Form
Tan, White, Black
Water ConditionsdKH 8-11, pH 8.1-8.4, sg 1.020-1.024,72-78° F,
Reef Compatible
With Caution
Size2-3 Feet


#8 Volitan Lionfish (Pterois volitans)

These fish not only look dangerous, they are!

The spines on the dorsal, pelvic, and anal fins are venomous and used for defense only. If you get stung by one of these fish the effect is like being stung by a bee or wasp, only stronger. Lionfish venom contains proteins that are broken up by heat, which prevent them from entering the bloodstream. Therefore not life threatening but very painful. However, you could suffer an allergic reaction to the venom so we advise you to seek medical attention as soon as possible.

These fish can grow up to 15″ in size and should be housed with fish of similar size. Anything smaller than bite size would soon become lunch!

These fish will eat shrimps and even some dried foods but mainly feed on live foods. Many people feed them goldfish and cheap freshwater fish but, be careful not to introduce disease into your tank.

These fish are certainly cool and will be the main attraction in any aquarium.

Scientific NamePterois volitans
Size15” Max
Tank Size100-130 Gallons
OriginCaribbean, Indonesia, Vanuatu
Reef CompatibleWith Caution
Water ConditionsSaltwater 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.021-1.023


#9 Fiddler Stingray(Trygonorhina fasciata)

This is a very stunning stingray that is suitable for larger saltwater aquariums and not too aggressive towards other fish. The tail spine is venomous but is only used for protection. Caution should be used when adding them to their new home or moving them. 

Netting them can be an issue with the tail spine, often getting stuck in the net and then you need to free it and that’s where most people get stung. If you do, you should seek medical attention immediately or call 911.

These fish will need a wide aquarium of at least 3 foot wide and around 500+ Gallon to thrive. They are classed as expert level fish. Careful consideration should be given when choosing a substrate for the bottom of your tank. These fish have a very sensitive underside and can scratch its abdomen and could cause an infection which is very difficult to treat.

They are also very sensitive to copper-based medications so be careful treating any infections or diseases within your tank hence the reason you should choose the substrate and decor carefully.

They are certainly a focal point in any tank I’ve seen them in and are really cool saltwater fish.

Scientific nameTrygonorhina fasciata
Size In Captivity around 12-24"
Yes- Tail Spine
Reef Compatible No
OriginCoral Sea
Water ConditionsSaltwater-72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Care LevelExpert
Tank Size500 Gallons+

dragonface pipefish

#10 Dragonface Pipefish (Corythoichthys sp.)

These saltwater fish are fascinating and always grab peoples attention when they see them in the home aquarium. They look like snakes and do in fact act like them in preferring to travel across rocks and substrate like snakes rather than swim.

They are very poor swimmers and spend most of their time holding onto rocks and substrate.

Dragonface Pipefish are sold in aquarium and pet stores worldwide and are often called different names like Reeftop Pipefish, Messmate Pipefish, Network Pipefish, and Banded Messmate Pipefish. In fact, to make things even more difficult there are 12 sub-species and all can have different colors and patterns making it very difficult to identify.

These pipefish love to eat the dreaded micro-amphipod commonly referred to as “Red Bugs” that has now become prevalent in reef aquariums that contain Acropora coral. This is great news as the Red Bug can affect your corals and cause them to discolor. So adding a few of these little fellas will help your corals thrive and reduce the number of red Bugs within your reef aquarium.

These are classed as expert level fish to keep due to their dietary requirements. A constant supply of baby live foods like Brine Shrimp and live copepods. If you have a large fully developed reef aquarium it will help, just don’t add them to a new reef tank or they simply will starve and die.

Scientific NameCorythoichthys sp.
OriginFiji, Indonesia, Maldives
Care LevelExpert
Aggression LevelPeaceful
Size7-8” Max
Water ConditionSaltwater: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Tank Size50 Gallons+
Reef Compatible?Yes

leaf fish

# 11 Leaf Fish(Taenianotus triacanthus)

These funny looking fish can be found in Hawaii, Maldives, and Indonesia perching on rocky areas looking for food.

They may look silly and harmless but they have poison glands attached to the dorsal, anal, and pelvic spines as a form of protection from predators.

They feed on small shrimp and feeder food should also be considered in the home aquarium. These solitary fish get their name from mimicking dead leave and laying around on the seabed looking for their next meal. Some also have a leafy appearance. 

One unusual characteristic of this fish is that they molt their skin twice a month to rid of algae and parasites from their skin, starting at the head and moving down its body. Leaf Scorpionfish are ambush predators and often rock back and forth with the current or tide, resembling leaves or drifting seaweed.

After molting and shedding their skin don’t be surprised if this fish has a whole new color!

Scientific NameTaenianotus triacanthus
OriginHawaii, Indonesia, Maldives
Care Level

Reef Compatible
With Caution
Size4-5” Max
Water ConditionsSaltwater:72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Tank Size 30 Gallons+

porcupine puffer

#12 Porcupine Puffer ( Diodon Holocanthus)

This was one of the first saltwater fish I ever owned and I love it. These fish have a personality all of their own. I had mine in a 200 Gallon open top tank and when he was hungry he would come to the top of the tank suck in water and spit it onto the floor. It was his way of saying “Feed Me.”

They normally keep their spines close by their side and only blow up when threatened or scared. They swallow water or air, causing their body to inflate to nearly twice its size and its spines to stand erect. An adult one can become the size of a football when fully inflated.

Mine hardly ever inflated, in the 7 years, I had him he only ever did it once when I introduce a larger fish into the aquarium and then it was only for a few minutes. A rare chance to see him in full glory.

They will often beg for food but don’t be fooled into feeding them everytime they ask it or you will be overfeeding them. Feed them 2-3 times a day with meaty foods and shellfish is adequate.

We do not recommend you keep one in a reef aquarium as they will attack and eat sessile invertebrates and will consume crustaceans and mollusks. If you do want to add them to a fully established reef aquarium make sure he/she is kept well fed with a good variety of foods. This will reduce the risk of them eating all your corals and sessile invertebrates. 

Scientific NameDiodon holocanthus
Care LevelModerate
Reef CompatibleNo
Tank Size150 Gallons+
Size12” Max
Water Conditions
Saltwater: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025

clown triggerfish

#13 Clown Triggerfish ( Balisoides Conspicillum)

Did we save the best until last? I think we might have. The Clown Triggerfish was always going to be on the 13 cool saltwater fish list and if this list was in order of coolness, I think I might have put it at number 1.

These fish can change appearance considerably from juvenile to adult but by far the most impressive is a fully grown male in full color.

They are classed as the jewel in the crown fish amongst saltwater fish keepers and command a high price!

Found in the wild in and around the external coral reef slopes at 60-80M.

These fish in the right environment make great community saltwater fish but they do have a bit of a Jekyll and Hyde personality. For months they will get along with all your other fish then can suddenly without warning attack and kill them.

Ensuring they have as much open water to swim in as possible to avoid territory fight is a must. Also, provide rocks and shelter for other smaller fish if they do decide to go on the attack.

These are very large and powerful fish and would be a match for any other tank mate. Feed them a varied diet of meaty crustacean and fish flesh. Once acclimatized to their new home and they become confident they can be trained to feed from your hand or a safer bet, from a long pair of tongs.

Feeding one of these fish on a one to one basis is an amazing feeling. These are such a wonderful and much-prized saltwater fish to own.

Scientific NameBalistoides conspicillum
OriginAustralia, Indonesia, Sumatra
Reef SafeNo
ColorBlack, Blue, Green, Orange, White, Yellow
Care LevelEasy
Unpredictable and often Aggressive
Size 13-18” Max in captivity
Tank Size250-300 Gallons+
Water ConditionsSaltwater: 72-78° F, dKH 8-12, pH 8.1-8.4, sg 1.020-1.025
Price$80 Juvenile - $700 Adults

Final Thoughts

We hope you liked these 13 cool saltwater fish? Of course, there are many more cool saltwater fish and I’m sure we will expand this post in the near future.

Which fish would you have added to this list? Let us know in the comments.

If it’s Freshwater fish you love then check out our latest post  Coolest freshwater aquarium fish.