Corresponding author: Miloš Vittori (
Academic editor: Ivan H. Tuf
The existing descriptions of the woodlouse
On the basis of new material collected in Slovenia, a description of the male morphology of
The genus
The terrestrial isopod
The present work reports on new material of
Isopods were collected by hand in Sežana, Slovenia. Live isopods were imaged using a DigiMicro Profi digital microscope and MicroCapture Pro software (both from DNT). All collected specimens were preserved in 96% ethanol. For light microscopy, pleopods and mouthparts were dissected with a pair of entomological pins and mounted in Euparal (Waldeck). Pereopods, uropods, antennae and mandibles were dissected with tweezers and mounted in glycerol. Whole specimens were imaged in 96% ethanol using an MZ FLIII stereomicroscope, equipped with a DFC425 C digital camera (both from Leica). Dissected appendages were imaged using an AxioImager Z.1 microscope equipped with HRc and MRm digital cameras (all from Zeiss), which was also used for fluorescence imaging with blue excitation (450-490 nm; Zeiss filter set 09) to visualise the structuring of the epicuticle. Drawings were prepared from micrographs using Illustrator software (Adobe). For scanning electron microscopy (SEM), the appendages and cephalothorax were transferred from 96% ethanol to pure acetone, air dried, sputter-coated with platinum and observed using a JSM-7500F field emission SEM (JEOL) at 5 kV acceleration voltage.
All specimens illustrated in the description, as well as three aditional females, were deposited in the Slovenian Museum of Natural History (PMSL-
Additional individuals were observed by chance in Paklenica National Park in Croatia, but were not collected. The observed isopods were photographed with a Samsung Galaxy S9 smartphone. To estimate their body-length, they were measured on photographs in comparison to features on the author’s hand.
Colour dorsally light greyish-brown with pale patches on bases of epimera on pereonites 2-7 and a median row of small pale patches on anterior edges of pereon tergites 4-7. Pleon with two faint lighter longitudinal lines. Ventrally, epimera and pereopods light grey, sternites and pleopods white. Posterior corners of pereon epimera in most specimens with faint orange patches less than one-fifth the length of epimeron (Figs
Cephalothorax and pereon tergites strongly tuberculate (Fig.
Lateral cephalic lobes twice as long as eyes, with straight outer margins and curved inner margins (Figs
Eyes (Fig.
Posterior margins of pereon epimera concave. Concave edges on pereonite 1 not evenly curved, instead with straight mid-section (Figs
Glandular pore fields on pereon epimera nearly circular, with diameter larger than distance to lateral margin of epimera (Fig.
Noduli laterales (Fig.
Pleotelson slightly longer than wide, with concave lateral margins converging strongly in anterior half of pleotelson and gradually in posterior half. Apex of pleotelson rounded (Fig.
Antennula (Fig.
Antenna (Fig.
Mandibles (Fig.
Maxillula (Fig.
Maxilla (Fig.
Maxilliped (Fig.
Male pereopod 1 (Fig.
Male pereopod 7 (Fig.
Pleopod exopodites 1-5 (Fig.
Male pleopod 1 exopod (Fig.
Male pleopod 2 exopod (Fig.
Uropod (Fig.
Lateral lobes of cephalothorax more than twice as long as median lobe and eyes. Acute angles between cephalic lobes. Distal article of flagellum of antenna at least twice as long as proximal article. Concave posterior margins of epimera on pereonite 1 not evenly curved, instead with straight segment in middle. Glandular pore fields on all pereonites circular and closer than their diameter to lateral edges of epimera. Carpus of male pereopod 7 dorsally with symmetrical, evenly curved crest reaching two-thirds length of carpus, highest point of crest in the middle. Lung fields on all pleopod exopods with convex, rounded edges. Male pleopod 1 exopodite with stout uniformly curved apical projection as long as width of lung field. Male pleopod 1 endopod with row of setae that curves as it approaches endopod apex and straightens abruptly at apex. Apex with tuft of setules.
East coast of the Adriatic Sea between Velebit (Croatia) and the Karst Plateau (Slovenia).
Amongst the material from Sežana, six juveniles were collected: two in October 2021 and an additional four in June 2022. The cephalic lobes are smaller in juveniles and the difference in length between the median and lateral lobes is not as pronounced as in adults. Three ovigerous females were collected at the same locality in June 2022.
Two additional individuals, a male (Fig.
The examined specimens of
The lack of records of
As discussed by Schmidt, male characters important to species identification in the genus
Some other European species of
Another morphologically similar species is
Although a total of 17 specimens were collected in this study, only one male was unfortunately available for microscopic examination. This makes it impossible to assess the possible variability of male characters between individuals of
I would like to thank Barbara Breznik, Gašper Breznik, Dea Borjančič and Lola the Frenchie, all of whom contributed to the collection of the isopods. I am also indebted to Tomi Trilar for his help in depositing specimens and Konstantin Gongalsky and Stefano Taiti for their valuable comments. This work was supported by the University Infrastructural Center “Microscopy of Biological Samples” at the Biotechnical Faculty, University of Ljubljana and the Slovenian Research Agency, research programme P1-0184.
Miloš Vittori collected and imaged the material and prepared the manuscript.
Live female
Structure of the dorsal body surface and antennula of
Appendages of cephalothorax and pereon,
Appendages of pleon,