Select the search type
  • Site
  • Web




Conchodytes biunguiculatus

Pontiniine Shrimp of the Black Lipped Pearl Oyster (Pinctada margaritifera)


 Alistair Lavers (2013)

Fact Sheet



Physical Description


Life History & Behaviour


Anatomy & Physiology

Evolution & Systematics

Biogeographic Distribution

Conservation & Threats

References & Links

Life History & Behaviour


Due to the lack of literature on this particular species very little is known about their feeding habits. Despite this, footage of the animals feeding was obtained. The manner in which they feed, therefore, is now known, although their specific diet remains difficult to ascertain. Given that the individuals studied were induced to feed by the presence of phytoplankton, it seems likely that at least part of their diet consists of plankton. Takeda, Tamura & Washio (1997) reported that Pontonia pinnophylax similarly feed on suspended particles as well as the mucus of their holothurian hosts. While it is possible that C. biunguiculatus are similarly parasitic on their bivalvian hosts, no tissue damage was observed in any of the oysters opened. Of course, if damage to the oysters is indeed present it may simply not be visible, or minimal. Without further observation and research on this topic any further comments on the diet of C. biunguiculatus would be complete speculation. Remaining on such a speculative note, the fact that C. biunguiculatus spend the majority, or indeed all, their time inside Pinctada margaritifera may suggest that their diet is very similar to that of their host in that they simply 'steal' a small portion of the food gathered by the oyster. Once again, however, this is purely speculation.

Video 1: Feeding behaviour of an adult, male C. biunguiculatus. Note that it uses two separate feeding strategies: It appears to use its first set of legs (ie. the haired, secondary claws) to grab food particles from the water. It also uses a set of specialised maxilla with fan-like projections on the end to filter particles from the water, these appendages are periodically directed toward the mouth for feeding.


C. biunguiculatus's primary method of movement is via their well developed swimming tail holding the animal's pereopods. It beats these to achieve locomotion in much the same way that a yabby or shrimp would.

Video 2: The beating of the pereopods on a male C. biunguiculatus's tail allows for fast and effective locomotion.


Once again, very little is known about the reproductive habits of C. biunguiculatus. One thing is clear however: the species live in male female pairs within the same host oyster. Of the 3 oysters that contained the species, all contained a male-female pair. Why this is, however, is unknown.

 One a similar note, a single juvenile was found within a small oyster. Maintaining the current trend of inscrutability, why this juvenile was not part of a pair is unknown. Without more information as to the development of the species, it must be said that the sex of the juvenile is also unknown. Having said this,the juvenile was very similar in appearance to an adult male, although it maybe that the sexual dimorphisms present in the species do not develop until closer to adulthood.