Adinda sp "Grizzly Bear"

Don’t let the name fool you — this “Grizzly Bear” would rather pretend to be dead than do anything remotely energetic

Adinda sp. "Grizzly Bear" is a rare and highly sought-after species of isopod, notable for its unique appearance and calm demeanour. It is certainly one of my favourite isopod species that I keep. It belongs to the Scleropactidae family and is one of the few representatives of this family in the isopod hobby. Native to Vietnam in Southeast Asia, this species has only recently become more widely available, thanks to successful breeding efforts.

Appearance

  • Size: This is a large species of isopod, typically around 1.5cm, though some individuals can reach up to 2cm.
  • Colouration: Distinctive tri-banded pattern which is striking. This consists of a gold band, flanked by black and brown bands. The gold band is what makes this species pop.
  • Exoskeleton: Very thick and durable - among the thickest seen in current isopod species.
  • Facial Features: Notable for large rows of setae on the face, which is believed to be something to do with water movement or sensing moisture.

Behaviour

  • Extremely calm and known for being masters of playing dead. The first time I kept these I thought they had died, they didn’t move a muscle, no leg twitching, no scampering, just still. Turns out they just love to act dead, so don’t worry in most cases, they are probably just tricking you!
  • When handled, they often remain completely still and tuck in tightly, showing no leg movement.
    Tend to avoid active fleeing, which can cause concern for new keepers — but they’re typically just exhibiting their natural defence behaviour.
  • Overall, I like to say they live life in the slow lane.

Environmental requirements

  • Humidity: Prefer high humidity and will retreat into sphagnum moss to maintain moisture levels. With mine they spend around 80% of their time in the dampest parts of the enclosure in the moss.
  • Temperature: I keep them at 22–26°C. Can tolerate cooler conditions down to 20°C without issues.
  • Ventilation: They appreciate good airflow, so I aim for medium to high ventilation while keeping things humid.

Diet

  • Honestly, they’re not big eaters of the usual extras. Mine show little interest in vegetables, fish food, or protein that I provide. Nonetheless, I provide it just in case they do want some.
  • They seemingly thrive best with just leaf litter and decaying wood. I provide an abundance of leaf litter. Make sure to also provide leaf litter in the humid end with the moss, as this is where they spend most of their time.
  • Just like with any isopod species, calcium is a must for good exoskeleton health. I include calcium carbonate in my substrate mix and top it off with crushed eggshells and cuttlefish bone for good measure.

Breeding & Growth

  • This is definitely a slow-growing species. If you’re after fast results, they’re not the one.
  • They’re also slow to breed — not prolific like many other isopod species.
  • Captive breeding efforts only began successfully in 2023 (UK).
  • While reproduction is slow, the species shows a good survival rate — few individuals die off once established.

Unique Qualities

  • One of the very few Scleropactidae in the hobby.
  • Highly charismatic due to both their striking look and quirky behaviour.
  • Easy to keep compared to some other Vietnamese isopods, making them a good choice for keepers looking for something unusual but manageable.

Photo gallery