There are a few species of fish that are known to have blue fins and black spots. To identify the specific type of fish, we need to consider key characteristics like size, geographic location, habitat, and distinctive markings beyond just the blue fins and black spots.
Fish with Blue Fins and Black Spots
Some of the most common types of fish that can have blue fins and black spots include:
- Bluefish – A predatory saltwater fish found along the Atlantic coast of the US and Canada. They have an iridescent blue coloring on their backs that fades to silvery white undersides. The fins are tinged with blue and they have several rows of small black spots along their sides.
- Blue tang – A popular aquarium fish that is bright royal blue in color with bold black spots outlined in white. They have a vibrant yellow tail and fins edged with blue. Blue tangs live in coral reefs in the Atlantic and Pacific oceans.
- Cichlids – There are thousands of species of cichlids from Africa and the Americas that can display vivid blue coloration on parts of the body and fins along with black spotting. Examples are the electric blue cichlid, blue dolphin cichlid, and cobalt blue cichlid.
- Damselfish – Small, colorful reef fish found around coral reefs. Some varieties like the threespot damselfish have metallic blue fins and bodies with 3 prominent black spots. Others may have blue fins with many small black spots.
- Wrasses – These saltwater fish come in a myriad of colors. Fairy wrasses in particular can have brilliant blue fins and tail with small black spots on a yellow or whitish body.
- Parrotfish – Tropical reef fish that often have blue-green colored fins and small black dots. Examples are the Atlantic blue parrotfish and midnight parrotfish.
- Angelfish – Certain color morphs and hybrids of angelfish have electric blue accents on the fins and bodies with black spotting on the frontal area.
Identifying Specific Species
To identify the exact species of fish based on the blue fins and black spots, we need to look at additional characteristics such as:
- Body shape – Is the body laterally compressed like a damselfish or deep and rounded like a parrotfish?
- Size – Is it a smaller fish under 5 inches like a damselfish or large over 2 feet like a bluefish?
- Mouth – Is the mouth small like a tang or large and protruding like a grouper?
- Habitat – Is it found on coral reefs or in open ocean?
- Geographic location – What oceans or regions is it found in?
- Distinctive markings – Does it have any stripes, bands, or other colors beyond the blue and black?
- Fins – Are the fins spiky like a wrasse or broad like a parrotfish?
With these additional criteria, we can narrow down the exact species. For example, if the fish is small, laterally compressed, found on coral reefs in the Pacific with a yellow tail, it is likely a blue tang. A large predatory fish found in the Northwest Atlantic with a protruding jaw would be a bluefish.
Bluefish
One prime candidate for a fish with blue fins and black spots is the bluefish. Some key facts about the bluefish:
- Scientific name: Pomatomus saltatrix
- Average size: 20-35 inches, 8-14 lbs
- Lifespan: Up to 12 years
- Habitat: Coastal temperate and sub-tropical saltwaters around the world
- Range: Found in the Western Atlantic from Maine to Brazil, also off South Africa, Australia, New Zealand
- Diet: Voracious predators that hunt smaller fish in schools, including herring, anchovies, menhaden, and more
- Distinctive features:
- Silvery blue-green back fading to white underside
- Jaws filled with sharp, fang-like teeth
- Large protruding lower jaw
- Fins and tail edged in blue
- Several rows of small, oval black spots on sides
In terms of appearance, bluefish have an iridescent, metallic blue coloring along the top of their bodies that fades to silvery white on their undersides. Their lower jaw is large and protruding. The fins and tail have a distinctive blue tint and they have several rows of small, oval-shaped black spots along their sides.
Blue Tang
Another candidate is the royal blue tang or blue surgeonfish. Details include:
- Scientific name: Paracanthurus hepatus
- Average size: 6-10 inches
- Lifespan: 10-20 years
- Habitat: Shallow coral reefs
- Range: Throughout Indo-Pacific
- Diet: Herbivore that grazes on algae
- Distinctive features:
- Brilliant royal blue body
- Prominent black spots outlined in white
- Bright yellow tail
- Small white spines on base of tail
- Blue edging on fins
The royal blue tang has a bright solid blue body covered with bold black spots outlined in white. The eyes are yellow and the tail is a vivid yellow color. The fins are edged with blue and there are small white defensive spines at the base of the tail.
Cichlids
The family Cichlidae includes over 2000 species of fish. Many African and South American cichlids can display a bright blue coloration on parts of the body and fins along with black spotting. A few examples include:
- Electric blue cichlid – A stunning aquarium fish with an overall electric blue color and black dots. Native to Lake Malawi in East Africa.
- Blue dolphin cichlid – Bright blue fins and a blend of bars and spots on a grayish body. From Lake Malawi.
- Cobalt blue cichlid – Intense blue on the body with black stripes and spots. Native to Lake Tanganyika in Africa.
- Jack Dempsey cichlid – Metallic blue accents on face and fins with dark spots. Named after the famous boxer. Found in South America.
The key distinguishing feature of the thousands of cichlid species is the split dorsal fin. Most cichlids share common characteristics like a sloped forehead, single nostril on each side, and spiny rays on the fins.
Damselfish
Damselfish comprise the family Pomacentridae. These small, vibrantly colored reef fish have over 350 species. Some types of damselfish that can have blue fins and black spots include:
- Threespot damselfish – Solid blue body with 3 large black spots. One spot behind each eye and one on the upper rear of the body.
- Humbug damselfish – Pale yellow or white with many small black dots. Blue fins and tail with black spots.
- Azure damselfish – Blue fins and tail with black bands or spots. Whitish body color.
In addition to the blue fins with black spots, damselfish are recognizable by their elongated, laterally compressed bodies that are less than 5 inches long. Most species live their entire lives within a small territory on the coral reef.
Wrasses
Wrasses comprise the family Labridae and have over 600 species. These colorful fish inhabit tropical and temperate reefs around the world. Some wrasses with blue fins and black spots include:
- Fairy wrasse – Males have yellow bodies with bright blue fins and long tails marked with black spots. Females are brown with white fins.
- Bird wrasse – Females are green with black spots and brilliant blue fins. Males are primarily yellow and black.
- Pencil wrasse – Slender fish with yellow bodies covered in small blue spots. Fins are blue-green with black edges.
Distinctive wrasse features include thick lips, sharp canine teeth, and pointed snouts. Many species exhibit major color differences between juvenile, female, and male phases.
Parrotfish
Parrotfish are a group of over 100 species in the family Scaridae. They are named for their bright colors and prominent beak-like mouths used for biting off algae. Some parrotfish with blue fins and black spots include:
- Atlantic blue parrotfish – Overall blue-green color with small black dots covering the body and fins.
- Rainbow parrotfish – Males have blue-green fins and bodies marked with black spots and stripes.
- Midnight parrotfish – Indigo blue fins and tail with black spots. The body is dark brown or black.
Unique features of parrotfish include the fused teeth that form a parrot-like beak as well as a fold of skin over the gills that forms a inflated-looking forehead. Most species are sequential hermaphrodites, starting life as females and later transitioning to males.
Angelfish
Angelfish belong to the cichlid family Cichlidae. There are over 100 species, most of which do not have blue and black coloration. However, captive bred color morphs and hybrids exist with blue fins and bodies accented with black spots, such as:
- Electric blue angelfish – Deep blue bodies with black spots concentrated on the frontal area near the eyes and mouth.
- Blue pearlscale angelfish – White angels with blue tinting on fins and scales and scattered black spots.
- Da Vinci angelfish – Marbled blue and black pattern on bodies and fins.
Wild angelfish species are generally silver, yellow, or black. The blue and black varieties have been selectively bred by aquarists. All angelfish types have elongated, laterally compressed bodies and long flowing fins.
Identifying Mystery Fish
If you spot an unknown fish with blue fins and black spots, here are some tips for identifying it:
- Note the overall body shape and size. Is it laterally compressed or rounded? Small or large?
- Examine the mouth. Is it small or large? Are the teeth visible?
- Check for details on other fins beyond the blue. Do the tail or other fins have any coloration or markings?
- Look closely to see if the black spots have any distinct shape or patterning.
- Consider whether it was seen in saltwater or freshwater and if so, tropical or temperate waters.
- Take photos from multiple angles and consult a fish identification guide for your region.
Paying attention to these kinds of diagnostic features in addition to the blue fins and black spots can help pinpoint the species. If needed, ask local fisheries experts to positively identify the fish.
Summary
In summary, there are a diverse array of fish species that can exhibit blue colored fins and black spotting. Just some of the most common groups include bluefish, blue tang, cichlids, damselfish, wrasses, parrotfish, and angelfish. Identifying the exact species requires looking at details like overall size and shape, mouth characteristics, precise fin markings, geographic location, and habitat. With close examination and the process of elimination, even an unknown fish with blue fins and black spots can be properly identified.