Information, Batfish, Saltwater fish, Species

Yellowtail Damselfish: A Vibrant Saltwater Aquarium Species

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by Jason Matthews



The Yellowtail Damselfish is a vivid and lively species that brings life and color to any aquarium. This small but hardy fish is an excellent choice for beginner and intermediate fish owners looking to add variety to their pet collection. 


Scientific Name: Chrysiptera parasema
Common Names: Yellowtail Damselfish
Life Expectancy: 5-8 years
Adult Size: Up to 2,8 inches


HabitatCoral reefs
Care LevelModerate
Tank LevelAll levels
Minimum Tank Size30 gallons
Water pH8.1-8.4
Water Temperature24-28°C (75-82°F)
Water Hardness8-12° dKH
Tank MatesCompatible with other peaceful to semi-aggressive fish

Fun Fact Corner

As a fun fact, Yellowtail Damselfish is recognized for its distinctive territorial defense tactics. These fish are highly territorial, defending their homes ferociously against any perceived threat, including other fish and even divers in the wild. Scuba divers who have encountered them while diving on coral reefs have called them “Dive Devils” because of their behavior.


The Yellowtail Damselfish, also known as Chrysiptera parasema, belongs to the Pomacentridae family. It originated in the warm waters of the Atlantic Ocean and the Caribbean Sea. These fish, usually found in coral reefs, are noted for their territorial tendencies and outspoken demeanor. 

Appearance & Size

One of the most distinguishing characteristics of the Yellowtail Damselfish is its look. These fish are known for their vibrant yellow tail, which contrasts against their blue-green body. The body is coated with microscopic scales and has a streamlined structure, allowing fast and graceful swimming. 

The dorsal fin is long and spiny, but the pectoral fins are rounded and employed for balance. The Yellowtail Damselfish’s eyes are huge and expressive, adding to the species’ allure.

The Yellowtail Damselfish varies in size but can reach a maximum length of 7 cm. The Yellowtail Damselfish size is one factor that makes it an attractive choice for aquarium hobbyists, as it requires less space and resources compared to larger fish species.


The Yellowtail Damselfish is a sexually dimorphic species, meaning that males and females have distinct physical characteristics. Male Yellowtail Damselfish are often larger and more vibrantly colored, whereas females are smaller and more subduedly colored. 

Males may also have longer and more intricate dorsal fins in rare circumstances. In the home aquarium, these differences can be used to identify the gender of Yellowtail Damselfish. Understanding your pet fish’s gender can help you build a suitable living environment, give necessary care, and understand their social behavior and reproduction potential.


The behavior of the Yellowtail Damselfish is one of its most notable traits. These fish are well-known for their territorial and assertive personalities, making them a distinctive and fascinating addition to any home aquarium. Yellowtail Damselfish are known to develop and protect a specific area within the tank, and if they feel threatened, they may turn hostile towards other fish species. 

It is important to give appropriate space and structure in the tank to minimize aggressive behavior and preserve the well-being of all fish species. Despite their territorial nature, Yellowtail Damselfish may be fairly gregarious and energetic in the tank, swimming, and playing. 


When selecting tankmates for your Yellowtail Damselfish, it is important to consider their territorial and bold personality. If these fish feel threatened, they are known to form a distinct territory within the tank and may turn hostile against other fish species. To avoid conflict, find tankmates who are similar in size and temperament. 

Here is a list of good tankmates for the Yellowtail Damselfish:

Tank conditions

Providing the proper tank conditions is essential for the health and well-being of the Yellowtail Damselfish. These fish are tough and versatile, but it is important to provide an environment similar to their native habitat. A minimum tank size of 30 gallons is recommended, with plenty of hiding spots and structure to provide security and prevent aggressive behavior. 

The water temperature should be kept between 72-78°F, and the pH level should be between 8.1 and 8.4. To provide a healthy living environment for your pet fish, maintain good water quality and make regular water changes.


The Yellowtail Damselfish is an omnivorous species and requires a balanced diet to maintain optimal health. They eat a range of tiny invertebrates and algae in their natural habitat. 

A diversified diet of both dry and frozen food is advised in captivity. Brine shrimp, krill, mysis shrimp, and a high-quality marine pellet or flake food are all suitable choices. It is important to supply a diverse range of foods to ensure a balanced diet and prevent the emergence of malnutrition or deficiencies. 

To maintain water quality and prevent overeating, feeding in modest quantities several times daily is advisable rather than one massive feeding.


Breeding Yellowtail Damselfish in captivity is uncommon, although achievable under the right conditions. These fish are quite territorial; therefore, a large, mature tank with plenty of hiding spots is required for effective reproduction. A regular and balanced diet and proper water parameters such as temperature, pH, and specific gravity are also important.

The male Yellowtail Damselfish will construct a territory and convince a female to lay eggs within it in terms of breeding behavior. The male will then fertilize and protect the eggs until they hatch. When the fry hatch, they can swim and should be separated from the adult fish to avoid predation.


Yellowtail Damselfish, like all other pet fish, are prone to various diseases and illnesses. Parasitic, bacterial, and fungal infections are common health problems. It is important to keep the tank environment clean and healthy to prevent spreading illness.

Regular water changes, appropriate filtration, and stable water parameters are critical for disease outbreak prevention. Furthermore, watch for indicators of illness, such as loss of appetite, irregular swimming behavior, and apparent signs of infection, such as spots, ulcers, or hazy eyes.

In case of illness, it is important to seek the advice of a veterinarian experienced in fish health or a fish health specialist. Prompt treatment is essential in preventing the spread of disease and maintaining the health of the fish.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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