The genus Trichoniscoides Sars, 1899 (Isopoda: Oniscidea: Trichoniscidae) from Portugal, with descriptions of three new species Author Cifuentes, Julio Departamento de Biología (Zoología), Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain. jcifcol@gmail.com Author Da Silva, Luis P. CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto-InBIO, Universidade do Porto, Campus de Vairão, Rua Padre Armando Quintas, 4485 - 661 Vairão, Portugal. & BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485 - 661 Vairão, Portugal. lfpascoals@cibio.up.pt text European Journal of Taxonomy 2026 2026-01-27 1034 271 305 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3169/14093 journal article 314267 10.5852/ejt.2026.1034.3169 25fb9372-2142-4bbe-8cd8-d15538a2e8eb 2118-9773 18424372 EF4A6EC8-2A1B-4FE2-858B-4F4FA4CF9517

Table 1. Summary of comparative characters for species of the genus Trichoniscoides Sars, 1899 found in Portugal.

	T. bellesi Reboleira & Taiti, 2015	T. broteroi Vandel, 1946	T. gallaecus Cifuentes & Da Silva, 2023	T. lusitanus Vandel, 1946	T. machadoi Vandel, 1946	T. meridionalis Vandel, 1946	T. ouremensis Vandel, 1946	T. serrai Cruz, 1993	T. sicoensis Reboleira & Taiti, 2015	T. subterraneus Vandel, 1946	T. castanheirensis sp. nov.	T. cordovensis sp. nov.	T.oloensis sp. nov.
Pigmentation	no	no	dark red	orange-pink or bright red	orange to white	no	no	no	no	no	orange	orange, red	orange
Ocular apparatus	no	no	1 ocellus	1 ocellus	no/1 ocellus	no	no	no	no	no	1 ocellus	1 ocellus	1 ocellus
Integument	granulated	granulated	granulated	smooth	smooth	weakly granulated	granulated	granulated	smooth	smooth	granulated	granulated	granulated
Antennae with tubercles	yes	yes	yes	no	yes	yes	yes	yes	yes	yes	yes	yes	yes
♂ pereopod 1 differentiated	no	yes	no	no	yes	yes	yes	no	yes	yes	yes	yes	yes
♂ pereopod 7 differentiated	no	yes	yes	no	no	no	no	no	yes	yes	yes	yes	yes
♂ exopod I
shape	triangular	sub-quadrangular	trapezoidal	triangular	triangular	rectangular	triangular	triangular	quadrangular	triangular	trapezoidal	trapezoidal	triangular, with posterior internal lamina
notch	no	yes	no	yes	yes	no	no	yes	no	yes	no	no	yes
ciliated rami, internal relative to external	equal	slightly thinner	internal vestigial, external very long	thicker	equal or thinner	thicker	equal	thinner	thinner	much thinner	thinner	much thinner	thinner
♂ endopod I
shape	triangular	sub-rectangular	triangular	rectangular	trapezoidal	trapezoidal	triangular	triangular	rectangular	rectangular	triangular	triangular	rectangular
distal lobe	no	triangular, long	triangular, long	triangular, long	no	no	no	rounded, short, wide	triangular, short	triangular, very long	triangular, long	triangular, long	rounded, small
♂ exopod II
shape	no data	trapezoidal	trapezoidal	trapezoidal	trapezoidal	trapezoidal	trapezoidal	trapezoidal	trapezoidal	trapezoidal	rectangular	trapezoidal	trapezoidal
♂ endopod II
distal segment tip	thin	thin, in layer	thin, in layer	thin and straight	very thin	thin	thin, cylindrical, slightly curved	thin	thick with a complex tip	very thin, long and sharp	very wide, curved tip with rounded end	wide, with chitinous reinforcement	wide, with chitinous reinforcement
length ratio of distal to basal segments	2.2	3.6	3	3.5	4	3.6	3	1.8	1.5	3.6	1	2	2
Ecology	troglobiotic	troglobiotic	epigean	epigean	epigean	troglobiotic	troglobiotic	troglobitic	troglobiotic	troglobiotic	epigean	epigean	epigean