Slender rasbora
Rasbora daniconius
Also known as Blackline rasbora, Striped rasbora, Slender barb
FreshwaterFish
Care at a glance
- Temperature
- 72–81°F
- 22–27°C
- pH
- 6.0–7.5
- Adult size
- 3.9 in
- 10 cm
- Minimum tank
- 32 gal
- 120 L
- Temperament
- Peaceful
- Social behavior
- Schooling
- Swim level
- Middle
- Difficulty
- Easy
- Breeding
- Medium
- Rarity
- Common
- Family
- Cyprinidae
- Origin
- Widespread across South and Southeast Asia, from Sri Lanka and India to the Mekong basin.
Overview
The slender rasbora is a hardy, active rasbora that shoals in open midwater and grows larger than the common nano species. It is easy to keep.
Did you know
In older books, the slender rasbora was one of the standard beginner rasboras. The smaller nano species took over that role later.
Caring for the slender rasbora
Keep slender rasboras in a group of at least eight. They are active swimmers, so give them a tank of 32 gal (120 L) or more. A lid is wise, since they can jump.
Keep the water at 72 to 81°F (22 to 27°C) with a pH of 6.0 to 7.5, though they adapt to many conditions. Feed flakes, pellets and frozen or live foods such as daphnia, bloodworm and mosquito larvae.
Slender rasboras are peaceful and make good dither fish for larger community tanks. Breeding them is moderately difficult.
Good to know
The slender rasbora, Rasbora daniconius, has carried many common names, including blackline, striped and golden striped rasbora. Those names reflect its wide range and long history in the hobby. A bold dark stripe edged with gold runs the length of its slim silver body and catches the light as the shoal moves. Fish from different regions vary in size and exact color, and wild fish grow larger than tank fish.
In the wild
The slender rasbora lives in a huge range of streams, rivers, ponds and ditches. Its range runs from Sri Lanka and India into mainland Southeast Asia, as far as the Mekong basin.
Weekly picks
Tank mates
The slender rasbora is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.
Neocaridina shrimp
Neocaridina davidi
Freshwater1.6 in (4 cm) · 5 gal (19 L)59–84°F (15–29°C)
Guppy
Poecilia reticulata
FreshwaterBrackish2.4 in (6 cm) · 10 gal (38 L)64–82°F (18–28°C)
Neon tetra
Paracheirodon innesi
Freshwater1.5 in (3.8 cm) · 11 gal (40 L)70–77°F (21–25°C)
Yoyo loach
Botia almorhae
Freshwater6.3 in (16 cm) · 42 gal (160 L)66–81°F (19–27°C)
Common hatchetfish
Gasteropelecus sternicla
Freshwater1.6 in (4 cm) · 33 gal (125 L)68–82°F (20–28°C)
Long nosed arched cory
Corydoras narcissus
Freshwater2.8 in (7 cm) · 30 gal (115 L)73–77°F (23–25°C)
Common questions
What size tank does a slender rasbora need?
A slender rasbora needs at least 32 gal (120 L). It spends most of its time in the middle.
What temperature and pH does a slender rasbora need?
A slender rasbora is comfortable at 72–81°F (22–27°C) with a pH of 6.0–7.5.
What does a slender rasbora eat?
A slender rasbora eats flakes, pellets and frozen or live foods such as daphnia, bloodworm and mosquito larvae.
How big does a slender rasbora get?
An adult slender rasbora reaches about 3.9 in (10 cm).
Does a slender rasbora need a group?
Yes. A slender rasbora is a schooling species and should be kept in a group, not singly.
Related species
3.5 in (9 cm)29 gal (110 L)72–82°F (22–28°C)Brilliant rasbora
Rasbora einthovenii
3.5 in (9 cm) · 29 gal (110 L)
3.1 in (8 cm)32 gal (120 L)72–79°F (22–26°C)Sidestripe rasbora
Rasbora paviana
3.1 in (8 cm) · 32 gal (120 L)
5.5 in (14 cm)45 gal (170 L)72–77°F (22–25°C)Scissortail rasbora
Rasbora trilineata
5.5 in (14 cm) · 45 gal (170 L)
3.9 in (10 cm)34 gal (130 L)73–82°F (23–28°C)Clown rasbora
Rasbora kalochroma
3.9 in (10 cm) · 34 gal (130 L)
2.4 in (6 cm)18 gal (70 L)72–79°F (22–26°C)Red-tailed rasbora
Rasbora borapetensis
2.4 in (6 cm) · 18 gal (70 L)
1.8 in (4.5 cm)15 gal (55 L)73–79°F (23–26°C)Volcano rasbora
Rasbora vulcanus
1.8 in (4.5 cm) · 15 gal (55 L)