We have now finished digitising the Museum’s main parasitic louse slide collection – consisting of ~73,000 slides. We are sharing these openly with the global scientific community on the Museum’s Data Portal.
All the slides have been imaged using our high-throughput slide digitisation workflow described in our previous blog post. We have also taken high resolution images for example specimens of each species, either primary types or a representative.
The louse digitisation project not only aimed to digitise the louse slide collection but also to further refine the slide digitisation workflow. Whilst digitising the slide collection, we came across other louse related artifacts, including bird feathers from host specimens with lice eggs attached and lice specimens stored in paper envelopes. The collection also contains specimen stubs with lice that have been coated in gold – a conductive coating – to enable them to be imaged using a scanning electron microscope (SEM)
The next phase of the louse digitisation project is the extraction of data from the specimen labels into a digital format to facilitate on-going research. So far the country information for a third of the collection has been captured and indicates that the louse slide collection consists of a wide distribution of material with large quantities of material from the UK and former British colonies such as Australia, India, and Kenya. In addition, data associated with each specimen, such as where and when it was collected, and from which host, will help to provide invaluable information new host associations as well as geo-spatial distributions within a host’s range.
Adaptation to life in a marine environment
Few insect species have colonised the open ocean despite their success on land. There are a number of hypotheses about why this is. These hypotheses range from insects generally needing to breathe above water and thus restricted to living within surface water. This has problems from predation to finding a mate in a vast ocean, to that of crustaceans fill much of their niche. There are, however, some insects that can be found in the open ocean and these are lice from the family Echinophtiriidae that infest pinnipeds (sea lions, walruses and seals).
Some Pinnepeds can remain at a depth of 1500m for over two hours. This means that lice on these mammals are submitted to massive hydrostatic pressure. Aquatic mammals also spend periods of weeks to months submerged in the open ocean meaning that lice need to be able to survive cold temperatures and low oxygen environments.
Lice that infest marine mammals have physiological and behavioural adaptations to allow them to survive both a marine and terrestrial environment. In comparison to other species of lice, they have a much more rounded spherical body. They also have shorter, slender front legs in comparison to their strong middle and back legs. This may enable them to pierce the thicker skin of their hosts.
The Human head louse(Pediculus humanus) on the left, has a flattened oval body whereas a walrus louse (Antarctophthirus trichechi) on the right has a more muscular body.
The louse of the Northern fur seal (Antarctictophtirus callorhini) thrives on the naked parts of the seal: the nostrils, auditory canals and eyelids. It has short, pointed claws to help it hold on to flesh as well as a specialised structure on its abdomen to trap air bubbles.
Antarctophtirus callorhini lives on the Northern Fur seal.
As lice eggs can not survive at sea, Echinophtiriidae can only reproduce when their host remains on land for a long enough period. For marine mammals the longest period of time they remain on land is just after their birth. Marine mammal lice, unlike other louse species, react to temperature and will move from a nursing cow to her warmer pup, with pups becoming infested within hours of birth.
We need your help
There are twelve known species of Echinophthiriidae. The Museum holds hundreds of specimens of these marine dwelling lice, which we have digitally imaged and will be asking members of the public to help us transcribe the label information for each specimen on Friday 29 September, 18.00-21.30 BST at Science Uncovered. Science Uncovered is a free public event where you can meet our Scientists, take part in interactive science stations, and see behind the scenes of the museum after hours.
Visit us in the Earth Hall to transcribe these slides and contribute towards scientific research. With your help, we will make this data and information available to scientists on the Museum’s Data Portal. We enable free open access to these resources that could hold the answer some of the world’s big questions, such as the impacts of climate change, and how diseases affect wildlife and humans.
To stay in touch with the digital collection programme and our digitisation projects please visit the website or follow us on twitter.