Sulawesi Black Diamond Shrimp Breeding Guide (Caridina spinata)

Breeding the dark Sulawesi Caridina spinata 'Black Diamond': stable hard alkaline warm water, groups of ten or more, and direct-developing broods of about 20-30 shrimplets.

Overview

The 'Black Diamond' is a dark purple-black aquarium form of Caridina spinata, an Atyidae shrimp endemic to Lake Towuti in Sulawesi's Malili lake system, where the species occupies rocky slopes around 3-5 metres deep. It shares the Sulawesi profile: hard alkaline warm water and direct development, with hatchlings emerging as tiny adults rather than larvae. The wild species is Critically Endangered, affected by predatory introduced flowerhorn cichlids, aquarium-trade collection, and habitat pollution from activities such as nickel mining.

Conditioning

Aim for steady pH in the 7.8-8.5 range, GH about 6-8, KH 4-8 and warmth of 27-29 C, usually achieved with remineralised RO water and a Sulawesi mineral salt. Keep dissolved nutrients minimal, as the Malili lakes are nutrient-poor and the shrimp are not adapted to nitrate or phosphate buildup. The diet rests on biofilm and detritus grazed from hardscape, with only light supplementary feeding.

Breeding Setup

Use a biologically mature species tank from 40 litres with rockwork that echoes the natural rock slope. Keeping at least ten individuals reduces the stress these shy shrimp show and improves pairing. Filtration should be gentle yet well-established, and any new water must be matched to tank temperature and pH before it is added, because sudden shifts are poorly tolerated.

Spawning & Berried Females

Berried females hold roughly 20-30 eggs under the abdomen and fan them with the pleopods until they hatch after about 20-28 days. There is no planktonic larval stage; the young emerge as miniature copies of the parents. The moderate brood size means a healthy, stable group can build a colony steadily once water chemistry is reliable.

Shrimplet/Larval Care

Shrimplets need no brackish or salt phase and feed on the same biofilm and detritus as the adults from day one. Keep nutrient levels low and supplementary food fine and infrequent. The early weeks are most threatened by parameter instability, so any maintenance changes should be small and slow.

Common Challenges

The recurring problem is holding mineral-rich but alkaline, low-nutrient water at a stable warm temperature; these shrimp react strongly to changes in light and chemistry, making acclimation and transport risky. With the wild species Critically Endangered, captive-bred animals are the responsible source for new stock.