Research led by one of APEM’s scientists uncovered tiny differences between the mouth parts of various species of shrimp and suggested why they may have developed.

The team used an electron microscope to reveal the presence of hair-like cuticular structures on most of the mandibles. These striking features are barely discernible using light microscopes.

Observations on shrimp mandibles - Lead Image

Taxonomic research

APEM’s Dr Chris Ashelby, along with Dr Magnus Johnson of the University of Hull and Dr Sammy De Grave of the Oxford University Museum of Natural History, spend much of their time examining shrimp morphology.

They are looking for tiny differences between species. This led them to dissect the mandibles from nine related species of shrimp and study them using a scanning electron microscope.

Most modern taxonomic descriptions of shrimps describe the mandible and most show subtle differences between species.

Observations on shrimp mandibles 1

Intrigued by this, and knowing that most previous studies were performed using light microscopes, the team used an electron microscope to delve deeper, revealing a previously unrecorded diversity in form and structure.

Cuticular structures

The most striking feature of most the mandibles were hair-like cuticular structures, which under light microscopes are almost impossible to see. The arrangement, placement and form of these structures differed between species, suggesting that they also performed unique functions.

Observations on shrimp mandibles 2

The researchers determined five different sorts of cuticular structures and six basic forms of mandible in just the nine species included in the study. The team determined that different feeding modes and prey items required different mouth parts and that the shrimps have evolved mouth parts matched to the kind of prey they eat.

Lead researcher, Dr Chris Ashelby, said: “With around 3,500 described shrimp species, and untold diversity currently undescribed, we have barely scratched the surface in terms of what could be expected.

“Who knows what other adaptations may be found by looking at more shrimp species, as well as at other families, super-families or even other crustacean groups.”