Werner de Gier

Werner de Gier

Dutch PhD-candidate studying the evolution and ecomorphology of symbiotic crustaceans, living in and on tropical coral reef organisms, using CT-scanning and other figuration methods. Additionally focusing on science-communication and teaching.


Crustaceans, Symbiosis, Coral reefs, Ecomorphology, Marine Biology, CT-scanning

Werner de Gier MSc.

PhD student
Promotion at the University of Groningen
Marine Evolution & Ecology

@://www.instagram.com/werner_degieMailto: firstname.lastname@naturalis.nl 

52.164533900869, 4.4730637508841

PhD study
Crustacean Ecomorphology and Evolution

I use natural-history collections, various figuration methods and phylogenetic studies to shed light on the "Ecomorphology", the adaptations of an animal to a certain lifestyle, of symbiotic crabs, shrimp and other crustaceans, living in and on coral reef organisms.

Using the Naturalis crustacean collection, made world-famous by carcinologists like Holthuis, Buitendijk, and De Haan, I hope to shed more light on the evolution of symbiotic crustaceans, mainly focussing on crabs and shrimp. CT-scanning and other figuration methods make it possible to study the adaptations of a crustacean symbiont, living in or on a host organism. The study of these adaptations to fit a certain habitat and lifestyle, called Ecomorphology, can be combined with phylogenetic analyses to study the convergent evolution of obligate symbionts, but also the host switches which might have occurred in the evolutionary history of these taxa.

Pinnotheres pisum CT scan
Collection Decapoda 18L


  • de Gier W., Helleman P., van den Oever J., Fransen C.H.J.M. 2023. Ecomorphological convergence in the walking leg dactyli of two clades of ascidian‐and mollusc‐associated shrimps (Decapoda: Caridea: Palaemonidae). Ecology and Evolution 13 (12), e10768. doi.org/10.1002/ece3.10768
  • de Gier W., Fransen C.H.J.M. 2023. Polka-dotted treasures: Revising a clade of ascidian- and bivalve-associated shrimps (Caridea: Palaemonidae). Contributions to Zoology 92, 179–282. doi: 10.1163/18759866-bja10042
  • de Gier W., Groenhof M., Fransen C.H.J.M. 2022. Coming out of your shell or crawling back in: multiple interphylum host switching events within a clade of bivalve and ascidian-associated shrimps (Caridea: Palaemonidae). Contributions to Zoology 91, 166–198. doi:10.1163/18759866-bja10030.
  • Muller E, De Gier W, Ten Hove HA, Van Moorsel GWNM, Hoeksema BW - 2020 - Nocturnal Predation of Christmas Tree Worms by a Batwing Coral Crab at Bonaire (Southern Caribbean) - Diversity 12(12): nr. 455
  • De Gier W, Becker C - 2020 - A Review of the Ecomorphology of Pinnotherine Pea Crabs (Brachyura: Pinnotheridae), with an Updated List of Symbiont-Host Associations - Diversity 12(11): nr. 431
  • De Gier W, Fransen CHJM, Ozten Low A, Hoeksema BW - 2020 - Reef fishes stalking box crabs in the Southern Caribbean - The Scientific Naturalist // Ecology 101(8): e03068
  • Garcia-Hernández JE, De Gier W, Van Moorsel GWNM, Hoeksema BW - 2020 - The scleractinian Agaricia undata as a new host for the coral-gall crab Opecarcinus hypostegus at Bonaire, southern Caribbean - Symbiosis 81: 303-311
  • De Winter AJ, De Gier W - 2019 - A new Nigerian hunter snail species related to Ennea serrata d’Ailly, 1896 (Gastropoda Pulmonata:
    Streptaxidae) with notes on the systematic position of West African species attributed to Parennea Pilsbry, 1919 - Zookeys 840: 21-34.
  • Rowson B, De Gier W, De Winter AJ - 2019 - A species comes of age: new material and micro-CT scanning reveal the adult of Gulella
    bicarinata Blume from Kilimanjaro, Tanzania; with a discussion of Mirellia Thiele from Kenya (Pulmonata: Streptaxidae) - Journal of Conchology 43(3): 287-296.
  • De Gier W, De Winter AJ - 2018 - Micro-CT scanning Africa’s streptaxids – revealing the insides of Ptychotrema shells - The Malacologist 72.
  • De Gier W & Fransen CHJM - 2018 - Odontonia plurellicola sp. n. and Odontonia bagginsi sp. n., two new ascidian-associated shrimp
    from Ternate and Tidore, Indonesia (Crustacea, Decapoda, Palaemonidae), with a phylogenetic reconstruction of the genus - Zookeys 765: 123-160.
  • Jongbloed CA, De Gier W, Van Ruiten DM & Donovan SK - 2016 - Aktuo-paläontologie of the common cuttlesh, Sepia ocinalis, an
    endocochleate cephalopod (Mollusca) in the North Sea - Paläontologische Zeitschrift 90(2): 307-313.

All publications


  • Guest lectures about crustaceans during various courses
    • 1st year: Tree of Life - "Biodiversiteit Dier" - M. J. Hooykaas MSc.
    • 2nd year: "Biodiversiteit" - Prof. Dr. N. de Voogd
  • Part-time Student Assistant during practicals and excursions of various courses
    • 1st year: "Excursies Flora & Fauna" - Marine excursions

In the

Science-Communication plays a major role in my scientific career: I started writing for the Natuurwijzer, spend a lot of time on Twitter and wrote press releases for my own publications. In my spare time I like to work on SciComm projects like Through the Ocular, where I highlight a part of the Education-collection of the University of Leiden & Naturalis

Together with Dr. Charles Fransen we described two new species of Odontonia shrimp, of which one got named "The Hobbit Shrimp" - Odontonia bagginsi. The Hobbit shrimp, drawn here by artist Franz Anthony, got featured in international media and in the WoRMS top 10 marine species of 2018.

Odontonia bagginsi De Gier & Fransen 2018