My main research interest is the phenotypic (morphological) variability of decapod crustacean larvae as basis for adaptation to fluctuating environment and for evolutionary novelties. During my Master's thesis, I investigated this aspect on several examples within decapod crustaceans.

Crustaceans occur in various ecological systems and occupy numerous ecological niches, as they inhabit the oceans, freshwater, as well as terrestrial environments all over the world. They are important indicators of water quality and the efficiency of ecosystems. Throwing a plankton net into modern-day seas, one recognizes the abundance and diversity of crustacean larvae due to the shear numbers and differing morphological features. As crustaceans spend a large part of their life as larvae, this phase is especially prone to selective pressures. Thus, the adaptation of larvae to their environment is crucial for the evolutionary success of a species, and with this research on the larval sequences is of high importance. Especially investigating groups with a long larval sequence is advantageous for understanding developmental patterns and variation of morphological features. For this purpose, the very diverse, speciose and evolutionary successful group of decapods provides an appropriate system.

Morphological variability increases with a longer larval sequence, and especially the metamorphosis from the last zoea larva to the megalopa larva seems to underlie strong variability. All groups studied within my Master's thesis exhibit a variable morphology during the transition from zoea to megalopa, as there are intermediate forms with typical zoea features and megalopa features in the same stage. This indicates that this transition is much less distinct than proposed in literature, and that there is a stronger evolutionary and intraspecific variability of this transition from one larval phase to the following one.

For the documentation of extant and fossilised individuals I use different methods, e.g., fluorescence microscopy, composite macrophotography under polarised light, or stereo photography.

Grants:

03/2015: travel grant of GlaxoSmithKline for the Crustaceologists´meeting in Bremerhaven, Germany (400 €)

Publications:

Feldberg, K., Váňa, J., Krusche, J., Kretschmann, J., Patzak, S. D. F., Pérez-Escobar, O. A., Rudolf, N. R., Seefelder, N., Schäfer-Verwimp, A., Long, D. G., Schneider, H. & Heinrichs, J. 2016. A phylogeny of Cephaloziaceae (Jungermanniopsida) based on nuclear and chloroplast DNA markers. Organisms Diversity & Evolution 16(4), 727–742. DOI 10.1007/s13127-016-0284-4

Haug, J. T., Rudolf, N. R., Wagner, P., Gundi, P. T., Fetzer, L.-L. & Haug, C. 2016. An intermetamorphic larval stage of a mantis shrimp and its contribution to the 'missing-element problem' of stomatopod raptorial appendages. Annual Research & Review in Biology 10(3), 1–19. Free access PDF

Rudolf, N. R., Haug, C. & Haug, J. T. 2016. Functional morphology of giant mole crab larvae: a possible case of defensive enrollment. Zoological Letters 2, art. 17. Free access PDF

Haug, J. T. & Rudolf, N. R. 2015. A nisto larva of an Eocene slipper lobster (Neoscyllarida). Palaeodiversity 8, 113–119. Free access PDF Suppl.

Examples of conference contributions:

a) Talks:

Rudolf, N.R. (2015). Neues über fossile Decapodenlarven. Paläoentomologentreffen 2015, Bonn.

b) Poster:

Rudolf, N.R., Haug, C. and Haug, J.T. (2015). Defensive enrolment in arthropods - functional morphology of giant mole crab larvae (Hippidae). Annual meeting of the German Zoological Society (DZG) 2015, Graz.

Rudolf, N.R., Haug, C., Harzsch, S., Krieger, J., Hamasaki, K., Haug, J.T. (2015). Die Metamorphose des Palmendiebes Birgus latro (Decapoda, Coenobitidae). Crustaceologentagung 2015, Bremerhaven.