Ichthyocoris Bonaparte, 1840

Duquenne-Delobel, Emma, Doadrio, Ignacio & Denys, Gael P. J., 2022, Revalidation of the genus Ichthyocoris Bonaparte, 1840 (Actinopterygii: Blenniiformes: Blenniidae), Acta Ichthyologica et Piscatoria 52 (1), pp. 35-41 : 35

Ichthyocoris Bonaparte, 1840

(Fig. 1

Ichthyocoris Feminine gender

Type species.

Salarias varus Risso, 1827.

Synonyms.

Salariopsis Vecchioni, Ching, Marrone, Arculeo, Hundt et Simons, 2022 (see remarks below).

Included species.

Three species: Ichthyocoris atlantica (Doadrio, Perea et Yahyaoui, 2011), new combination; Ichthyocoris economidisi (Kottelat, 2004), new combination; Ichthyocoris fluviatilis (Asso y del Rio, 1801), new combination.

Material examined.

Ichthyocoris atlantica : MOROCCO • 1; Ouerrha River at Ouazzane; MNCN 280135 (2, 48-61 mm SL) • see Doadrio et al. (2011).

Ichthyocoris economidisi : GREECE 10; Lake Trichonis; MNCN 120747-120756 • see Kottelat (2004) and Doadrio et al. (2011).

Ichthyocoris fluviatilis : FRANCE • 2; Tet River at Perpignan; 42°42′21′′N, 002°54′04′′E; Persat and Denys coll. leg.; MNHN-IC-2013-0674 . SPAIN • 10; Ebro River at Zaragoza; MNCN 13657-13666 • see Kottelat (2004) and Doadrio et al. (2011) .

Diagnosis.

Ichthyocoris is distinguishable from Salaria by the presence of brownish bars on the flanks not contrasted with black dots conferring a marble coat (Fig. 1 ) (vs. brownish bars on the flanks very contrasted with blue stripes and dots conferring a marbled coat; Fig. 2 ); dorsal-fin slightly notched between spined and soft rays (Fig. 1 ) except for I. atlantica (vs. not notched; Fig. 2 ); 16-18 dorsal-fin soft rays (vs. 21-27); 16-20 anal-fin soft rays (vs. 20-28); 34-38 vertebrae (vs. 38-44); 8-9 circumorbital pores (vs. 6-7); 8-11 preopercular pores (vs. 6-8); 3 supratemporal pores (vs. 2) (Table 1 ).

Distribution.

Ichthyocoris is present in drainages of the Mediterranean basin, in catchments of the Atlantic coast in Morocco and Spain as well as in the Black Sea.

Ecology.

All Ichthyocoris species occur in freshwaters. However, due to their marine ancestry, I. fluviatilis has a one-month planktonic larval phase ( Gil et al. 2010) and a high tolerance for salt water ( Plaut 1998), allowing migration through marine waters ( Perdices et al. 2000; Almada et al. 2009; Laporte et al. 2016; Méndez et al. 2019; Wagner et al. 2021).

Remarks.

Comparing our diagnosis with the description of Salarias varus from Risso (1827), the three species do belong to the genus Ichthyocoris : the presence of dark dots on the body, 29 dorsal-fin spined and soft rays, and 19 anal-fin spined and soft rays. In the same fashion, comparing characters of S. basilisca and S. pavo with the diagnosis of Gadus salaria from Walbaum (1792), both species belong to the genus Salaria : the presence of 36 dorsal-fin spined and soft rays and 26 anal-fin spined and soft rays.

Other characters may discriminate between both genera: Papaconstantinou (1977a) distinguished I. fluviatilis from S. basilisca and S. pavo by the two lateral ethmoid bones between the median ethmoid and the vomer (vs. median ethmoid connected to the vomer). However, this character state is shared by other blenniids and needs to be checked within the two other Ichthyocoris species. Similarly, karyotype studies pointed out differences between I. fluviatilis and S. pavo (heterochromatin concentrated on the entire arm of two chromosome pairs like Lipophrys spp., vs. homogeneous distribution of heterochromatin like Parablennius spp. ( Cataudella and Civitelli 1975; Unal et al. 2016). This character needs to be explored as well to characterize both Ichthyocoris and Salaria genera.

In a recent study, Vecchioni et al. (2022) also split the genus Salaria , distinguishing marine Salaria spp. from freshwaters species. They described a new genus Salariopsis with Blennius fluviatilis Asso y del Rio, 1801 as type species (mentioning erroneously the new combination Salariopsis fluviatilis ) and grouping as a new combination Salariopsis fluviatilis , Salariopsis economidisi , and Salariopsis atlantica . This new genus is distinguished from Salaria by 16-17 dorsal-fin soft rays (vs. 22-27) and 16-19 anal-fin soft rays (vs. 23-28) from only bibliographical references ( Bath 1977; Kottelat 2004; Doadrio et al. 2011; Tiralongo 2020). Their diagnosis is similar to ours for Ichthyocoris for these two characters. Thus, Salariopsis and Ichthyocoris designate the same taxa. However, the nomen Ichthyocoris Bonaparte, 1840 is older than Salariopsis Vecchioni, Ching, Marrone, Arculeo, Hundt et Simons, 2022. Thus, the principle of priority must be applied (art. 23.1 ICZN): Ichthyocoris must be the valid nomen and Salariopsis , its junior synonym.

Kottelat (2004) suspects a population from Lake Kinneret (Israel) to belong to a distinct species. Molecular studies confirm that populations of the Eastern Mediterranean basin form a distinct evolutionary lineage ( Doadrio et al. 2011; Geiger et al. 2014; Belaiba et al. 2019; Wagner et al. 2021). Another evolutionary lineage in the Guadiana catchment of the Atlantic basin from Spain was also highlighted with molecular data ( Perdices et al. 2000; Almada et al. 2009; Doadrio et al. 2011; Belaiba et al. 2019; Méndez et al. 2019; Wagner et al. 2021). These two evolutionary lineages may correspond to two new Ichthyocoris species if morphological characters were to be found.

Figures

Figure 1. Lateral view of Ichthyocoris spp.: I. atlantica, MNCN 280135, 61 mm SL, Morocco, Ouerrha River (Sebou drainage) at Ouazzane (A; photo credits: I. Doadrio); I. economidisi, MHNG 2641.89, holotype, 60.8 mm SL, Greece, Lake Trichonis east of Panetolio (B; photo credits: R. Covain); I. fluviatilis, 89 mm SL, Spain, Jerea River (Ebro drainage) at Virues (C; photo credits: I. Doadrio).

Figure 2. Lateral view of Salaria spp.: S. basilisca, MNHN-IC-A- 1779, syntype, 138 mm SL, Italy: Mediterranean Sea at Genoa (A; photo credits: J. Pfliger); S. pavo, MNHN-IC- 2012 - 0254, 74 mm SL, Balearic Islands at Menorca (B; photo credits: S. Iglesias).