Ichthyosquama amphoralis (Penard, 1905) Soler-Zamora & Useros & González-Miguéns & Gómez-Rodríguez & Lara, 2023

Soler-Zamora, Carmen, Useros, Fernando, González-Miguéns, Rubén, Gómez-Rodríguez, Pablo & Lara, Enrique, 2023, The problem of ‘ shadow species’ as illustrated with the taxonomic hotchpotch Cyphoderia ampulla (Rhizaria: Cyphoderiidae), Zoological Journal of the Linnean Society 199 (2), pp. 477-492 : 488-489

Ichthyosquama amphoralis (Penard, 1905) comb. nov.

( Figs 1 , 6 C 1 )

Zoobank registration: urn:lsid:zoobank.org:act:CA3A8AC0-5410-43B4-B80D-E4EC47E7D75B .

Ichthyosquama catoirensis Soler-Zamora, Useros, González-Miguéns, Blanco-Rotea, Carrasco-Braganza, Salvador-Velasco, Guillén-Oterino, Tenorio-Rodríguez & Lara sp. nov.

( Figs 1 , 6 C 3 ; Model 1)

Zoobank registration: urn:lsid:zoobank.org:act:8996A03C-3944-4FF2-A53E-B8133191F313 .

Type locality: Catoira , Galicia, Spain (42º 40ʹ N 8º 43ʹ W) .

Habitat: Freshwater sediment and mosses.

Measurements: 116.21–146.77 μm length, 45.80–71.80 μm width, 16.17–19.62 μm pseudostome large axis (N = 9).

Specific diagnosis: Elongated test composed of imbricated scales, bent neck.

Intraspecific variability: Large variability in the general shape of the test. Most have the typical shape of the genus, with an oval, slender test, a flatter ventral side, a rounded fundus, and a curved neck. However, the shape can be more rhomboidal and the fundus can be pointier or flatter.

Differential diagnosis: Ichthyosquama catoirensis can be diagnosed from other members of the genus by its specific sequence of the mtDNA marker and its phylogenetic position. The morphometric analyses performed in this work can separate this species from other members of the genus.

Etymology: We propose this name as a reference to the type locality Catoira (Galicia, Spain).

Holotype: MA-Amoeba 11265.

Ichthyosquama loricaria Soler-Zamora, Useros, González-Miguéns & Lara sp. nov.

( Figs 1 , 6 C 4 )

Zoobank registration: urn:lsid:zoobank.org:act:496DE5E9-54CD-43F4-82EB-74BB3CB508C4 .

Type locality: Rhodopes , Bulgaria (41º 59ʹ N 24º 10ʹ E) .

Habitat: Freshwater sediment and mosses.

Measurements: 96.25–129 μm length, 36.30–47 μm width, 13.18–16.38 μm pseudostome large axis (N = 108).

Specific diagnosis: Elongated test composed of diagonal rows of round, imbricated scales. The scales are generally partially fused together. Rounded fundus. The ventral side is slightly flattened. There is a thin layer of cement around the aperture and in two individuals we could count a series of 16–17 tear-shaped scales around the interior side of the aperture. The size of the visible part of the scales is generally 3.12–3.77 × 2.62–3.11 μm.

Differential diagnosis: Ichthyosquama loricaria can be diagnosed by its specific sequence of the mtDNA marker and its phylogenetic position. The presence of tear-shaped scales around the inner part of the aperture can differentiate it from I. amphoralis . We did not observe the presence of this trait in other species.

Etymology: The epithet refers to the catfish family Loricariidae and to the genus Loricaria based on its resemblance to these animals due to the imbricated scales. The lateral position of the aperture is reminiscent of the sucker mouth typical of members of the Loricariidae . Loricaria also means coat of mail in Latin, which could refer to the test of imbricated scales.

Holotype: BG-IBER-INV-000016458.

Ichthyosquama sanabriensis Soler-Zamora, Useros, González-Miguéns, Blanco-Rotea, Carrasco-Braganza, Salvador-Velasco, Guillén-Oterino, Tenorio-Rodríguez & Lara sp. nov.

( Figs 1 , 6 C 2 )

Zoobank registration: urn:lsid:zoobank.org:act:49306CC6-C109-4647-946F-221358100DB7 .

Type locality: Lake Sanabria , Spain (42º 10ʹ N 6º 44ʹ W) .

Habitat: Freshwater sediment and mosses.

Measurements: 102.93–150.35 μm length, 38.82–60.03 μm width, and 14.30–19.89 μm pseudostome large axis. The size of the visible part of the scales is generally 3.22–3.91 × 2.47–2.92 μm (N = 109).

Specific diagnosis: Elongated test composed of diagonal rows of imbricated scales. Posterior end generally rounded and ventral side generally flattened. In two specimens, we counted 17 oral scales.

Intraspecific variability: We found some individuals in which the outline of the test was somewhat rhomboidal, or slightly flattened at the very end. One particular (abnormal?) specimen had its test bent like a sickle, thus having a concave ventral side.

Differential diagnosis: Ichthyosquama sanabriensis can be diagnosed by its specific sequence of the mtDNA marker and its phylogenetic position. The morphometric analyses performed in this work separates this species from other members of the genus.

Etymology: We propose this name as a reference to the type locality, Lake Sanabria (Castilla y León, Spain).

Holotype: MA-Amoeba 11266.

Figures

Figure 1. Bayesian phylogenetic tree based on SSU and COI sequences of the family Cyphoderiidae.At each node posterior probability values (Bayesian analysis) and bootstrap values (Maximum Likelihood analysis) are represented.The colours represent the molecular clades. GenBank accession codes are given on the tips. Species names correspond to the taxonomic assignation of the organisms based on morphology for each lineage.

Figure 2. A, Linear discriminant analysis of four continuous morphological traits.B, Number of shells classified into their own clade under the linear discriminant analysis.C, Linear discriminant analysis of four continuous morphological traits of clade C. D, Linear discriminant analysis of four continuous morphological traits of clade A.

Figure 3. Dichotomous key of the family Cyphoderiidae.New genera are in bold with their respective shell outline drawing (50 μm scale bar), scale arrangement under SEM (grey box with 10 μm scale bar), and shell outline under light microscopy (orange box) in order to differentiate them. (A) Cyphoderia; (B) Oleiformis gen. nov.; (C) Ichthyosquama gen. nov.: (D) Knarr gen. nov., (E) Psammoderia gen. nov.

Figure 4. SEM images of C. ampulla and the different UCS from the Cyphoderiagenus. Insets show the typical habitat for each organism.The original drawing of C. ampulla from Ehrenberg, 1840 is shown top right.The white bars represent a scale of 10 μm and the black one 50 μm for each organism.

Figure 6. SEM images of the different species of Ichthyosquama gen. nov. Insets show the typical habitat for each organism.At the bottom right of the two previously known species, the original drawing is represented.The coloured squares at the top left of each image have the same colour as the clades to which each taxon corresponds in Fig.1. The white bar represents a scale of 10 μm and the black bar 50 μm for each organism.