Whisker Shrimp Breeding Guide (Macrobrachium lanchesteri)

Breeding the predatory whisker shrimp Macrobrachium lanchesteri: green-saddled females carry eggs on their pleopods, larvae may follow abbreviated or extended (brackish) development, and adults must be separated from their young.

Overview

Macrobrachium lanchesteri is a translucent freshwater prawn of the family Palaemonidae, widely distributed across mainland Southeast Asia and noted as the most abundant and widespread Macrobrachium in freshwater ecosystems, particularly in lentic (still-water) habitats. Often sold as a 'ghost shrimp', it is more predatory than true Palaemonetes and will hunt small fry and dwarf shrimp. Within Macrobrachium, species are split into abbreviated larval development (ALD) types and extended larval development (ELD) types, the latter requiring brackish or sea water; this distinction sets the breeding strategy.

Sexing

As in other Macrobrachium, mature males tend to develop longer, more robust claws while females are identified by their egg-carrying behaviour. A green 'saddle' (a spot behind the back of the head) marks a gravid female, after which she moves the developing eggs to her pleopods on the underside of the abdomen.

Conditioning

Keep adults in stable freshwater within the species' tolerated range and feed an omnivorous diet, since well-fed adults breed more readily. Because the shrimp is semi-aggressive and predatory, conditioning is best done in a species tank rather than among small tankmates that could be eaten. Lentic, vegetated set-ups reflect the still-water habitats where the species is most abundant in the wild.

Breeding Setup

A 40-litre or larger tank with plenty of cover suits a small breeding group. The key question is larval development type: ELD Macrobrachium need brackish or salt water for the larvae and may pass through 6-14 larval stages over roughly 2-12 weeks, whereas ALD species complete development in freshwater. Plan a separate rearing vessel, and be ready to add salt if larvae fail to develop in freshwater, since landlocked freshwater populations of this prawn do occur.

Spawning & Berried Females

After mating the female carries the eggs on her pleopods until they hatch. Once larvae hatch the mother should be removed, as Macrobrachium females will prey on their own larvae. Reflecting the freshwater colonisation seen across the genus, brood care is extended and relative fecundity and larval stage count are reduced compared with marine-spawning relatives.

Shrimplet/Larval Care

Newly hatched larvae are tiny and need fine live or powdered food; small meaty foods such as Artemia nauplii are used for related whisker shrimp. If the population is an ELD type, the larvae must be reared in brackish or salt water and transitioned to freshwater as they metamorphose; ALD larvae can be raised in freshwater throughout. Survival is poor without close attention to food size and water quality.

Common Challenges

The main uncertainty is whether a given stock follows abbreviated or extended larval development, which determines whether brackish water is required. The adults' predatory nature means larvae and juveniles must be separated from hungry adults, and the species should never be bred alongside dwarf shrimp or small fish it would hunt.