Ponticola alasanicus, Epitashvili & Japoshvili & Mumladze, 2023

Epitashvili, Giorgi, Japoshvili, Bella & Mumladze, Levan, 2023, Ponticola alasanicus sp. n. (Gobiiformes, Gobiidae) from the Alazani River Basin, Georgia, Biodiversity Data Journal 11, pp. 101095-101095 : 101095

Ponticola alasanicus sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: HIDPal1 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal1; individualCount: 1; sex: male; lifeStage: adult; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 90162319-7839-579C-9EB1-E1F5C8E0D687; Taxon: taxonID: SCCBO130-22 - 1007251; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; scientificNameAuthorship: Epitashvili, Japoshvili and Mumladze 2023; vernacularName: Alazani goby; Location: locationID: Alazani River; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin ; country: Georgia; countryCode: GE; stateProvince: Kakheti; county: Telavi; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; dateIdentified: Bella Japoshvili; Levan Mumladze; identificationRemarks: DNA barcoding; Event: samplingEffort: 1; eventDate: 11-Aug-2020; year: 2020; month: August; day: 11; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Paratype. Occurrence: catalogNumber: HIDPal1 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal1; individualCount: 1; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 503A9C0F-959F-5928-BBB4-2D352EADA131; Taxon: taxonID: SCCBO122-22 - 1007242; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: DNA barcoding; Event: samplingEffort: 1; eventDate: 11-Aug-2020; year: 2020; month: August; day: 11; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Paratype. Occurrence: catalogNumber: HIDPal1 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal1; individualCount: 1; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: EB90F6D3-169C-56EB-9E5B-68C90403BEDE; Taxon: taxonID: SCCBO131-22 - 1007252; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: DNA barcoding; Event: samplingEffort: 1; eventDate: 11-Aug-2020; year: 2020; month: August; day: 11; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Paratype. Occurrence: catalogNumber: HIDPal1 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal1; individualCount: 1; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: D59DD48D-957E-5FA7-BCB6-CAD685B8C637; Taxon: taxonID: SCCBO132- 22 - 1007253; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin ; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: DNA barcoding; Event: samplingEffort: 1; eventDate: 11-Aug-2020; year: 2020; month: August; day: 11; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Paratype. Occurrence: catalogNumber: HIDPal1 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal1; individualCount: 1; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 8F567408-B657-5672-9F93-920C883F5ACC; Taxon: taxonID: SCCBO133-22 - 1007254; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: DNA barcoding; Event: samplingEffort: 1; eventDate: 11-Aug-2020; year: 2020; month: August; day: 11; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Other material. Occurrence: catalogNumber: HIDPcy2 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPcy2; individualCount: 1; sex: male; lifeStage: adult; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: A8526592-C88A-5387-B64A-B3464AC36F6A; Taxon: taxonID: HIDPcy2; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: Morphology & DNA barcoding; Event: samplingEffort: 1; eventDate: 26-Dec-2020; year: 2020; month: December; day: 26; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Other material. Occurrence: catalogNumber: HIDPal2 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal2; individualCount: 1; sex: female; lifeStage: adult; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 81E8A0FB-89DE-519E-90A2-32214DE555F6; Taxon: taxonID: HIDPal2; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: Morphology & DNA barcoding; Event: samplingEffort: 1; eventDate: 26-Dec-2020; year: 2020; month: December; day: 26; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Other material. Occurrence: catalogNumber: HIDPal2 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal2; individualCount: 1; sex: female; lifeStage: adult; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 0BE084FB-16C0-5895-B408-4962BAF78837; Taxon: taxonID: HIDPal2; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: Morphology & DNA barcoding; Event: samplingEffort: 1; eventDate: 30-May-2022; year: 2022; month: May; day: 30; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Other material. Occurrence: catalogNumber: HIDPal2 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal2; individualCount: 1; sex: female; lifeStage: adult; reproductiveCondition: pregnant; establishmentMeans: native; occurrenceStatus: present; preparations: fin clip; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 60686D75-310B-5299-86C3-4F1010A91CFA; Taxon: taxonID: HIDPal2; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: Morphology & DNA barcoding; Event: samplingEffort: 1; eventDate: 30-May-2022; year: 2022; month: May; day: 30; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU Type status: Other material. Occurrence: catalogNumber: HIDPal2 ; occurrenceRemarks: Captured during the electro fishing; recordedBy: Giorgi Epitashvili; individualID: HIDPal2; individualCount: 1; sex: male; lifeStage: adult; establishmentMeans: native; occurrenceStatus: present; preparations: whole specimen; previousIdentifications: Ponticola cyrius; associatedSequences: BOLD:AEO718; occurrenceID: 2C25F16A-0C05-55B3-9192-CD0F8FD82059; Taxon: taxonID: HIDPal2; scientificName: Ponticola alasanicus Epitashvili, Japoshvili & Mumladze, 2023; originalNameUsage: Ponticola alasanicus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Gobiiformes; family: Gobiidae; genus: Ponticola; taxonRank: Species; vernacularName: Alazani goby; Location: locationID: Alazani River ; higherGeographyID: Kakheti Region; higherGeography: Caucasus; continent: Eurasia; waterBody: Western Caspian Sea Basin; country: Georgia; countryCode: GE; stateProvince: Kakheti; municipality: Telavi; locality: Shakriani ; verbatimLocality: Telavi-Eniseli connecting bridge; maximumElevationInMeters: 347; verbatimLatitude: 41.988808; verbatimLongitude: 45.577726; Identification: identifiedBy: Giorgi Epitashvili; identificationRemarks: Morphology & DNA barcoding; Event: samplingEffort: 1; eventDate: 30-May-2022; year: 2022; month: May; day: 30; habitat: River; Record Level: type: PhysicalObject; language: EN; rightsHolder: Ilia State University; institutionID: ISU Ilia State University; collectionCode: Actinopterygii; ownerInstitutionCode: ISU

Description

Holotype: ISU - SCCBO130-22 - 1007251; Male, 73.5 mm TL, 61.0 mm SL; Georgia, Kakheti Region, Western Caspian Sea Basin, Tsitsmatiant Psha, right tributary of the Alazani River, near the Telavi-Eniseli connecting bridge, N41.988808, E45.577726; (collecting date: 11-Aug-2020).

Paratypes: ISU - SCCBO122-22 - 1007242, ISU - SCCBO131-22 - 1007252, ISU - SCCBO132- 22 - 1007253, ISU - SCCBO133-22 - 1007254, 52.0 - 71.0 mm TL, 42.0 - 59.0 mm SL, same data as holotype.

Additional materials used in morphological analyses: ISU - HIDPcy2, male, 71.0 mm TL, 58.5 mm SL; ISU - HIDPal2, female, 45.0 mm TL, 38.0 mm SL; ISU - HIDPal2, female, 69.0 mm TL, 57.0 mm SL; ISU - HIDPal2, female, 63.0 mm TL, 52 mm SL; HID - Pal2, male, 74.0 mm TL, 59.0 mm SL, same data as holotype/paratypes. Remark: these specimens were captured during resampling in 26-Dec-2020 and 30-May-2022 in the same location.

Description: D1 VI, D2 I / 16½, A I / 12½, l.l. 53. Body laterally compressed, gradually tapering from head to tail; minimum body depth almost 1.4 times less than caudal peduncle length; lateral parts of the body covered by ctenoid scales; first and second dorsal fins almost touching with their bases; second dorsal fin of uniform height; head large, depressed, wider than deep, its length approaches almost 3.4th its SL; nape scaled completely; cycloid scales cover upper part of opercle, cheeks noticeably swollen; snout longer than eye; eye diameter 4.5 times its HL; lower jaw slightly protruding; upper lip is uniform; pelvic disc elongated, not concave but flat, its length about 1.6 times less than ventro-anal distance, not reaching anus; pectoral fins reach base of first dorsal branched ray; caudal fin rounded.

The colouration of the preserved holotype yellowish-grey with dark brown and black blotches on the body (Fig. 2 ). The upper part of the head is dark, the throat white with yellow-marble colouration; the same colouration is present in the upper and lower parts of the whole body; on the last part of the caudal peduncle, there is a dark spot in the shape of a cross; the predorsal area is linearly concave in the middle with dark brown and black scales; vertically arranged uneven spots follow the lateral sides of the whole body; ventral disc with white/marble colouration, pectoral, dorsal, anal and caudal fins yellowish-grey; first and second dorsal-fin with some brown stripes and blotches; first three unbranched dorsal fin rays with dark stripes and, in upper part, transparent/white; dark brown spots on the upper part of the pectoral fin base. Body proportions and morphometric characters are given in Table 2 .

Extended description based on all type specimens: Overall meristic characteristics: D1 VI-VII, D2 I / 15½-16½, A I / 10 ½-12½; l.l. 48-55. All studied specimens have a relatively short body, laterally compressed at caudal peduncle, the maximum length (TL) was fixed as 73.5 mm in holotype; 15½-16½ branched dorsal rays; 10½-12½ branched anal rays; scales in lateral line series from 48 to 55; minimum body depth is 1.3-1.5 times its caudal peduncle length; head relatively large, depressed, wider than deep, its length 3.1-3.7 times its SL; head width slightly larger than depth at nape, interorbital distance short from 2.0 to 3.0 mm; lower jaw slightly protruded, upper and low jaws same length; lips almost uniform, upper lip slightly swollen; pelvic disc short, elongated and flat, not reaching anus. In our samples, the largest specimen was a male with 59.0 mm SL and 74.0 mm TL. Sexual dimorphism is not pronounced, except that males are slightly longer than females.

Colouration: Live specimens have yellowish-grey colour with dark brown and black blotches on the body (Fig. 3 ). Some goby species, for example, P. hircaniaensis ( Zarei et al. 2022) distributed in the southern Caspian Basin have a similar colouration. Studied specimens after fixation in 96% molecular grade ethanol are usually yellowish-grey with dark brown and black blotches on the body. Some specimens also have brownish colouration on the head. The abdomen is white/marbled. Pelvic disc with white/grey colouration; pectoral, dorsal, anal and caudal fins yellowish-grey; first and second dorsal-fin with some brown/dark or grey stripes and blotches; first dorsal fin ray with dark stripes and, in upper part, transparent/white in some specimens; dark brown spots on the upper part of the pectoral fin base.

Head lateral-line system in Ponticola alasanicus sp. n. is similar to the other known species from the genus Ponticola (Fig. 4 ): neuromast organs form seven transverse rows, four (1 - 4) before, one (5) in parallel and two (6 and 7) above hyomandibular row b, row 7 consists of several papillae before anterior oculoscapular pore α; three (C, C1 and C2) under PN and lacking row a. One hyomandibular row (S1) above PN and another one (S2) above AN, respectively. Lacking papillae row 5i and 6i. Row 5 and 6 long, papillae row (O) above oculoscapular pore γ. Sub-orbital longitudinal row d consists of three parts: the anterior d1 oblique, following the border of the upper lip and not reaching below the anterior origin of d2, the posterior longitudinal row d2 and d3 are related to each other. Anterior and posterior oculoscapular canals and pre-opercular canals present with pores σ, λ, κ ω, α, β, ρ, θ, τ and γ, δ, ε, respectively. Anterior oculoscapular pore ρ and posterior oculoscapular pore θ well-separated, row X1 between them, row X starts from pore β and reaches pore θ.

Diagnosis

D1 - VI, D2 I / 15½-16½, A I / 10½ - 12½; nape scaled completely, scales cycloid and ctenoid, cycloid scales covering upper part of opercle; lateral line system with sub-orbital row d continuous; predorsal area is linearly concave in middle; first dorsal fin with oblique black stripe between first two or three rays, the tip of the first 3-4 rays is transparent white; species has one large dark spot at the base of the pectoral fin; ventral disc has oval/elongated shape, short, not reaching anus.

Differential diagnosis

Ponticola alasanicus sp. n. is distinguished from other species of the genus Ponticola entering freshwater habitats in the Caspian Sea Basin by the following characters:

It can be distinguished from P. syrman by fewer scales in mid-lateral series (48-55 vs. 57-67+2-3); relatively short body (maximum size 73.5 mm TL vs. 220 mm TL); cycloid scales on the nape (vs. ctenoid scales); the ventral disc is slightly shorter (16.7 -19.7 vs. 19.0-20.0% SL) and shorter pre-anal distance (56.7-60.8 vs. 61.3-64.4% SL); P. alasanicus sp. n. does not have transverse infraorbital papillae rows below longitudinal hyomandibular row b (vs. P. syrman has three rows).

Ponticola alasanicus sp. n. is distinguished from P. iranicus by relatively small body-size (42.0-61.0 mm SL vs. 65.0-83.0 mm SL); fewer scales in lateral series (48-55 vs. 55-60); pectoral fin reaching to second dorsal fin (vs. not reaching); minimum body depth almost 1.4 times less than caudal peduncle length (vs. 1.5-1.9 times in P. iranicus ); interorbital distance particularly large from 1.3 to 1.5 mm in eye diameter compared to 0.3-0.8 mm in P. iranicus ; absence of transverse infraorbital papillae rows bellow longitudinal hyomandibular row b (vs. P. iranicus has two rows: 5i and 6i).

Ponticola alasanicus sp. n. differs from P. patimari by a ventral disc that is noticeably shorter (16.7-19.7 vs. 20.2-26.0% SL), not reaching anus (vs. reaching in some specimens of P. patimari ); additionally, there are seven transverse rows in P. alasanicus sp. n. comapred to six transverse rows in P. patimari ).

Ponticola alasanicus sp. n. is also distinguished from the recently described P. hircaniaensis Zarei, Esmaeili, Kovačić, Schliewen & Abbasi, 2022 from the southern Caspian Sea Basin by a lower number of scales in the mid-lateral series (48-55 vs. 52-59) and a relatively short head depth at nape (43.3-53.1 vs. 70.9-81.0%).

Ponticola alasanicus sp. n. is distinguished from P. gorlap by having a longer maximum body depth (21.6-24.6 vs. 15.0-18.1% SL); a longer least depth of caudal peduncle (12.0-14.3 vs. 7.8-9.4% SL); cycloid scales on the nape and predorsal area (vs. ctenoid scales in P. gorlap ); less scales in mid-lateral series (48-55 vs. 68-72 + 3-4); interorbital distance large (1.3-1.5 times vs. 0.8-0.9 times in eye diameter) and noticeably small body length (vs. TL in P. gorlap is almost three times larger).

Ponticola alasanicus sp. n. differs from P. cyrius by having an elongated and flattened ventral disc (vs. round and concave ventral disc); anterior membrane of ventral disc with shallow, slightly excised lobes (vs. deeply cut and angular in P. cyrius ); P. alasanicus sp. n. has longer least depth of caudal peduncle (12.0-14.3 vs. 9.4-10.0% SL); shorter head width (66.7-81.2 vs. 81.4-100.0%); predorsal area with dark brown and black colouration (vs. marbled).

Ponticola alasanicus sp. n. is distinguished from all other Ponticola species (e.g. P. constructor , P. rhodioni , P. rizensis and P. turani ) occurring in the Caucasian Black Sea Basin by following characters: P. alasanicus has fewer branched rays in dorsal fin 15½-16½ vs. 16½-19½ in P. constructor and P. rhodioni and 17½-19½ in P. turani and P. rizensis , respectively. P. alasanicus is also easily distinguished from the aforementioned gobies by noticeably short body (maximum reported SL = 61 mm) and elongated, short and flat-shaped ventral disc (vs. round and concave, with relatively long size ventral disc).

Etymology

The species is named after the Alazani River.

Distribution

Ponticola alasanicus sp. n. is endemic to the Alazani River Basin and currently known from the type locality (Tsitsmatiant Psha) and also from the small swamps near Shakriani (N42.001151 E45.600603) and Mshvidobiani (N41.76147 E46.130432) villages. Most likely inhabiting similar tributaries and habitats of the aforementioned river basin.

Ecology

The new species inhabits small to medium-sized rivers called “Psha” (which means clear, cold water in Georgian and which can be used for drinking) with sand and plant substrate (Fig. 5 ). These rivers rise from the ground and are typical for the Mtkvari, Alazani and Iori River lowlands.

Conservation

The new species has a small range (i.e. less than 20 km2) and is known only from the restricted area of the Alazani River Basin. The surrounding area of the known occurrences is within agricultural land where extensive use of pesticides and fertilisers is common. In addition, water intake from the river and illegal fishing are frequent (personal observation). Thus, we assume strong anthropogenic impacts on the habitat. Currently, the population trend is unknown. However, due to its extremly small range and high anthropogenic pressure, the conservation status of Ponticola alasanicus sp. n. can be regarded as vulnerable ( IUCN 2012).

Biology

Inhabits lowland rivers and swampy habitats with sand and plant bottom. Often found near submerged trees and roots. Feeds on aquatic invertebrates. Spawns in May-June.

Figures

Figure 2. Ponticola alasanicus sp. n. holotype; ISU - SCCBO 130 - 22 - 1007251, male, 73.5 mm TL, Georgia, Tsitsmatiant Psha (Alazani River Basin). Scale = 1 cm.

Figure 3. Live specimen of Ponticola alasanicus sp. n. from the type location.

Figure 4. Diagram of head lateral-line sensory system in the holotype of Ponticola alasanicus sp. n.; pores are designated by Greek letters, rows of neuromasts (genipores / sensory papillae) by Latin letters and Arabic numerals; AN - anterior nostril, PN - posterior nostril.

Figure 5. Type location - Tsitsmatiant Psha stream, right tributary of the Alazani River, typical habitat of Ponticola alasanicus sp. n.