Gammarus pseudosyriacus

Zamanpoore, Mehrdad, Grabowski, Michal, Poeckl, Manfred & Schiemer, Friedrich, 2011, Taxonomic review of freshwater Gammarus (Crustacea: Amphipoda) from Iran, Zootaxa 3140, pp. 1-14 : 9-10

Gammarus pseudosyriacus Karaman & Pinkster, 1977

Gammarus syriacus (part.) Chevreux, 1895: 160 –164, Figs. 6, 8, 9.

G. pseudosyriacus Karaman & Pinkster, 1977: 56 –58, Fig. 22; Khalaji-Pirbalouty & Sari, 2004: 2429 –2430; Ebrahimnezhad, Hosseini & Sari, 2005: 222, Fig. 2.

G. arduus ( Mateus & Mateus, 1990: 277, no figures), misidentified.

G. laticoxalis ( Mateus & Mateus, 1990: 278) , misidentified.

G. m i a e Mateus & Mateus, 1990: 293–298, Figs. 4–4a, new synonym.

G. p l u m i p e s Mateus & Mateus, 1990: 298–301, Fig. 5, new synonym.

G. syriacus ( Khalaji-Pirbalouty & Sari, 2004: 2429) , misidentified.

Locus typicus. Small pools around Damascus, Syria.

Material examined. Many specimens from Rahimi river, 13 km W Izadkhast (52°05'N, 31°25'E) ( FAIC 111001); Bavanat river, 35 km SE Bavanat (30°20'N, 54°00'E) ( FAIC 111012); Kooshkezar spring, 5 km S Shahremian (30°49'N, 52°20'E) ( FAIC 111021); Dashte Arjan spring, 60 km W Shiraz (29°39'N, 51°58'E) ( FAIC 111100); Kuhmare Sorkhi, 39 km W Shiraz (29°25'N, 52°10'E) ( FAIC 111275); Atashkade, 5 km N Firuzabad (28°53'N, 52°15'E) ( FAIC 111276 -1); Garme, 110 km N Shiraz (30°30'N, 52°30'E) ( FAIC 111286); Komehr spring, 25 km N Sepidan (30°27'N, 51°51'E), ( FAIC 111287).

Three specimens misidentified as G. arduus , 90 km S Abadeh (31°09'N, 52°39'E), Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4859).

Six specimens misidentified as G. laticoxalis , 68 km S Yazd (coordination is not given), Yazd Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4861).

Holotype of G. m i a e, 67 km NW Abadeh, Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4873); paratypes, 50 km W Shiraz, Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4876); paratypes, 67 km NW Abadeh, Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4908); paratypes, 90 km S Abadeh, Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4875).

Holotype G. plumipes , 56 km W Shiraz (29°36'N 52°32'E), Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4877); one paratype, 56 km W Shiraz (29°36'N 52°32'E), Fars Province, leg. Pretzmann 1970, det. Mateus & Mateus ( NHMW Amphipoda 4907).

Misidentified as G. s y r i a c u s. Five specimens, Beedak spring (31°47'N, 51°06'E), Chaharmahal va Bakhtyari Province ( ZUTC amph. #?), many specimens, Bizhgerd spring (31°43'N, 51°10'E), Chaharmahal va Bakhtyari Province ( ZUTC amph. 2040).

Distribution. Distribution range of this species in Iran was reported up to this time to be a vast area of the northern, central, and southern Zagros and its eastern outskirts facing the Great Central Basin ( Mateus & Mateus, 1990; Khalaji-Pirbalouty & Sari, 2004; Ebrahimnezhad et al., 2005). Unpublished data suggest their presence also in the province of Kerman in the far endings of southern Zagros Mountains. As revealed from our analysis of the literature data and own collections, G. pseudosyriacus is one of the two most widely distributed gammarid species in Iran ( Fig. 1 ).

Ecological notes. Having a wide range of tolerance to temperature (usually 5–21ºC) ( Khalaji-Pirbalouty & Sari, 2004), the species is often found in “desert-like” regions with water temperatures occasionally up to 34ºC ( Karaman & Pinkster, 1977). Data from recent sampling done by the first author in Fars province showed a variation of water temperature from 11 to 25 ºC (Mean = 15 ºC, SD = 3). Springs with populations of the species were found at altitudes ranging from 905 to 2600 m asl (Mean = 2165 m, SD = 252). Electric conductivity in these waters ranged from 120 μS/cm to 1015 μS/cm (Mean = 362 μS/cm, SD = 169).

Taxonomic remarks. The species can be confused with G. lacustris and G. lordeganensis , but the elevated postero-dorsal surface of urosomites 1–3 ( Karaman & Pinkster, 1977, Fig. 22J) helps to distinguish it from the two latter species. G. pseudosyriacus shares also several features with G. bakhteyaricus , the latter being different with the 2–3 tiny spines on ventral-distal corner of first peduncle segment of antenna 1. Another similar species is G. paricrenatus , differing from G. pseudosyriacus by long setation on ventral side of peduncle segments 4 and 5 in antenna 2, and by the crenulate setose postero-dorsal margin of pereosomites.

Misidentifications of this species might have arisen primarily from its wide distribution in the Zagros region and a relatively high level of intra-specific morphological variation. Among the variable features are degree of sharpness in postero-distal corner of the third epimeral plate, height of dorsal surface elevation in urosomites 1–3 (eg. case of confusion with G. syriacus ), degree of forward extension in antero-distal region of the first coxal plate (eg. case of confusion with G. laticoxalis ).

Misidentifications. Gammarus arduus . Our examination of the material in NHMW revealed that it was misidentified and that in reality the individuals in question belong to G. pseudosyriacus . Besides, G. arduus is a species with distribution restricted only to the Balkan Peninsula with no records in Asia Minor.

Gammarus laticoxalis . Based on our examination of the material, record of the species from Iran is a case of misidentification. Most possible explanation is that the degree of forward extension in antero-distal region of the first coxal plate in G. pseudosyriacus is variable to some extent, which might lead some authors to confuse it with G. laticoxalis . However, all other morphological characters are absolutely consistent with G. pseudosyriacus .

Gammarus miae . Type material shows no morphological differences from the type material of G. pseudosyriacus . It is quite apparent to us that this is another case of misidentification, and that the species is a junior synonym of G. pseudosyriacus .

Gammarus plumipes . The species was described based on a unique feature of having plumose setae on both anterior and posterior margin of all segments of pereopod 3. However, our examination of the holotype did not prove existence of such structure. Instead, numerous setae were covered by minute debris particles that made impression of plumosity. Thus the examined material was evidently identical with G. pseudosyriacus . In conclusion we propose G. plumipes as a junior synonym of G. pseudosyriacus .

Gammarus syriacus . There are three different samples from Iran misidentified as G. syriacus ; after revision they were reclassified to G. pseudosyriacus , G. shirazinus , and G. zagrosensis . Different degree of sharpness in postero-distal pointed corner of epimeral plate 3, and different level of elevation in the dorsal surface of urosomites 1– 3 might have caused incorrect misidentification of the above three species with G. syriacus . Moreover, presence of the species was also denied in Turkey ( Özbek & Ustaoġlu, 2006).

Figures

FIGURE 1. Distribution map of freshwater Gammarus species in Iran (grey regions indicate high mountainous areas).