Gammarus loeffleri, Zamanpoore, Mehrdad, Grabowski, Michal, Poeckl, Manfred & Schiemer, Friedrich, 2010

Zamanpoore, Mehrdad, Grabowski, Michal, Poeckl, Manfred & Schiemer, Friedrich, 2010, Two new Gammarus species (Crustacea, Amphipoda) from warm springs in the south-east pre-alpine area of the Zagros, Iran: habitats with physiological challenges, Zootaxa 2546, pp. 31-51 : 41-49

Gammarus loeffleri n. sp.

( Figs. 7–10 )

Material examined. Many males and females. Male holotype, body length 12.5 mm., February and August 2007, coll. M. Zamanpoore. Locus typicus: Cheshme Golabi spring, 23 km W of Darab, Fars Province, Iran (28˚47΄ N, 54˚22΄ E), Alt. 1100 m. Paratypes, many males and females; same date and locality. Additional samples: Aab Do-man-nim spring, 12 km S of Kherame, (28˚42΄N, 54˚27΄E), Alt. 1090 m.; Aab Vohli spring, 22 km S of Kherame, (28˚42΄N, 54˚27΄E), Alt. 1090 m.; Atashkade spring, 13 km N of Firooz Abad, (28˚53΄N, 52˚32΄E), Alt. 1366 m.; Bahadoran river, 15 km W of Darab, (28˚42΄N, 54˚27΄E), Alt. 1090 m.; a small river in Bande Amir road, 41 km E of Shiraz, (29˚33΄N, 52˚58΄E), Alt. 1570 m.; Fasa river, 5 km N of Fasa, (29˚01΄N, 53˚38΄E), Alt. 1430 m.; Ghare Aghaj river, 53 km S of Shiraz, (29˚11΄N, 52˚38΄E), Alt. 1650 m.; Nowbandegan, 20 km SE of Fasa, (28˚50΄N, 53˚49΄E), Alt. 1250 m.; Oghlanghez spring, 30 km NW of Darab, (24˚50΄N, 54˚24΄E), Alt. 1540 m.; Pa-Naal spring, 10 km NW of Fasa, (29˚07΄N, 53˚27΄E), Alt. 1520 m.; Sarve Nokhodi, 105 km SE of Shiraz, (29˚11΄N, 53˚06΄E), Alt. 1490 m.; Tang Aab spring, 29 km N of Firooz Abad, (29˚02΄N, 52˚34΄E), Alt. 1540 m. Type series are kept in the amphipod collection of the Museum of FARSAGRES, Shiraz, Iran. Holotype is deposited in the Zoological Museum of the University of Amsterdam ( ZMA, Amph. 206055, 2008). Distribution of the species is shown in Figure 1 .

Diagnosis. A small species with elongated eyes; this species can be distinguished from other similar species by combination of these characters: (1) highly setose antenna 2, (2) pereopod 7 basis without protruding lobe but with setae on postero-distal corner, (3) pointed postero-distal corner of epimeral plates 1– 3, (4) long setae on dorsal of urosome, (5) long setae on anterior margin of pereopods 5–7, (6) long spines mixed with setae on anterior and posterior of carpus and merus in pereopods 5–7, (7) and long setae on telson apex and surface.

Etymology. We take honour in naming this species for the late Professor Heinz Loeffler of the University of Vienna, in gratitude of his founder contribution to Iranian limnology, especially his studies on Lake Niriz, which is in the same geographical area of the present work. The whole study was planned to be conducted under his supervision, before he passed away in 2006.

Description. The description is based on the examination of the holotype, 10 male and one female paratypes.

Male. Maximum body length in 18 samples 14 mm. Lateral cephalic lobes more or less rounded, anterior lower extension of the head weekly developed; eyes elongated (longer than the diameter of the antenna 1), twice as long as wide, and reniform ( Fig. 7 C).

Antenna 1: generally long, about 2/3rd–3/4th the total body length; third peduncle segment is slightly shorter than the first and the second; groups of setae on lateral mid-length of peduncle segments 2 and 3; main flagellum with 27–30 segments with very short setae; accessory flagellum with 3–4 segments ( Fig. 7 A).

Antenna 2: Gland cone short, reaching to ca. the half of the length of the third peduncle segment; peduncle segments 4 and 5 with the same lengths, with dense groups of long setae (more than twice the length of the diameter of the segments); flagellum with 11–16 segments, not swollen nor compressed; groups of setae on the tip of the flagellum segments at dorsal and lateral faces, additional row of setae implanted submarginal to the distal of each segment at its ventral surface, setae on flagellum are shorter than peduncle segments and do not form a flag-like brush; three to six calceoli from segment 2 on ( Fig. 7 B).

Mandible: Incisor processes and lacinia mobilis well developed, in addition of a plumose long spine row and a ridged molar process ( Fig. 7 D). In mandible palp, ventral setation of the second segment include ventral setae, 3–5 shorter (as long as or a little longer than the width of the segment) single setae at proximal and 4–6 longer (longer than twice the width of the segment) setae in a row at distal; inferior margin of the third segment armed with a comb-like row of 18–20 D-setae, 5 long E-setae, one group of A- and one group of Bsetae ( Fig. 7 E).

Labium: Simple, with a group of short setae on the inner lobe apex, and a group of very fine bristles on inner and outer lobes.

Maxilla 1: Inner lobe with long setae having fine plumes; 8–10 stout serrate spines on outer lobe; right palp with five to six short and stout spines on the apex, one longer separate spine on its distal outer corner and a setae near it ( Fig. 7 I); on the apex of the left palp is an armature of four to five spines and a longer setae ( Fig. 7 H); variations in the strength of spines in some individuals ( Fig. 7 G).

Maxilliped: Exopodite having three–four strong teeth and three–four longer setae at the distal margin; a row of long setae at distal sub-margin which becomes plumose from the middle and continues towards the inferior margin to join to 6–7 very long plumose setae, a strong spine with a distance at sub-marginal interior corner ( Fig. 7 F); endopodite has a row of strong plumose setae on distal margin which continues to the half of the interior margin, while the setae gradually shorten, get stronger spine-shaped, and lose plumosity; a row of long setae on the whole of interior sub-margin shortening proximally, a row of very fine and long setae on the whole of exterior margin; the pulp is well developed.

Gnathopod 1: Coxal plate rectangular with rounded corners, antero-distal corner with 3–5 and posterodistal corner with one short setae, 2–4 longer setae on the postero-distal surface; distal 2/3rd of basis is wider, slightly expanded at 1/3rd, gradually gets narrower proximally; carpus posterior margin with groups of strong plumose setae; propodus pyriform, palm oblique, having both medial palmar and palmar angle spines, posterior propodus margin with a row of 3–5 groups (1–2 each) of spines, continuing proximally with one– two groups of long setae, 1–2 groups of very short spines (1–2 each) on posterior propodus sub-margin, 2–3 groups of fine short setae comes behind them proximally; 2–3 groups of setae at propodus anterior margin; dactylus is long, a group of four long setae very close to medial palmar spine ( Fig. 8 A).

Gnathopod 2: Distal of coxal plate slightly narrower than proximal, anterior distal corner with 3–4 and posterior corner with one short setae, 2–3 longer setae on the surface in posterior distal position; posterior margin of propodus is straight so that makes a rectangular shape, palm is more or less oblique with a robust medial palmar and 3 palmar angle spines; a group of setae beneath the medial palmar spine, 2–3 groups of setae at propodus anterior margin ( Fig. 8 B).

Pereopod 3: All segments bear groups of setae at posterior margin, about 1–2 times as long as the diameter of the segments, those of merus and carpus are in dense groups; merus on anterior margin with two groups of mixed setae and one spine, and a same group at anterior tip; anterior margin of carpus with a spine among first three proximal groups of setae, a long spine and a group of longer setae at anterior tip and the same but with two long spines at posterior tip; anterior margin of propodus with 5 groups of one small spine and some longer setae, the last of which does not reach to the anterior tip; coxal plate rounded at distal, concave at posterior, and convex at anterior margin, four small setae implanted at distal anterior and one at distal posterior margin ( Fig. 8 C).

Pereopod 4: Similar to pereopod 3, but the basis is wider; merus on anterior margin with a group of two short setae and two shorter spines on the middle of the segment, and another group of long setae mixed with two long spines at anterior tip; carpus with 2 spines and a group of long setae at posterior tip; anterior margin of propodus with 4 groups of one small spine and some longer setae; coxal plate expanded at posterior distal half, with 4 small setae implanted at distal anterior and 7 at distal posterior corner ( Fig. 8 D).

Pereopod 5: Basis sub-rectangular and slightly concave at posterior margin, backward protruding lobe at posterior distal developed, posterior margin with 13 very short setae, a row of 2–4 setae and 3–4 spines mixed with a very fine seta at anterior margin; merus and carpus anterior margin with long spines and setae (longer than spines, about 1–2 times than the segment’s width), with shorter and less dense setae at posterior; anterior margin of propodus with 6–7 rows of spines ((1–)2–3–3–3–3–2) mixed with setae, and 5 rows of longer setae at posterior ( Fig. 9 A).

Pereopod 6: Similar to pereopod 5, but longer, with longer setae on propodus and carpus anterior and posterior margin; basis is more slender and posterior proximal is slightly expanded, postero-inferior protruding lobe poorly developed ( Fig. 9 B).

Pereopod 7: Basis wider proximally; protruding lobe not developed and the postero-inferior corner is set with 1–3 setae, 14 small setae on posterior margin, starting from the very base of the basis; anterior of merus and carpus with long spines and much longer setae; merus and carpus posterior margin with 2 groups (1–2 each) of spine(s) mixed with some shorter setae; propodus anterior with 6 rows of spines (1–2–2–2–2–2) mixed with longer setae, posterior margin with 4 groups of long setae; few long spines at posterior tip of propodus along with a group of longer setae ( Fig. 9 C).

Uropod 3: Endopodite less than 2/3 of the exopodite (ratio of endo-/exopodite length ca. 0.6); very long spines on the distal margin of basis, few setae and 0–1 spine on the basis body; exopodite with long spines at distances on external margin; endopodite with 1–2 spines on external margin; long setae on both external and internal margins of endo- and exopodite, many of which on outer margins are plumose ( Fig. 9 F).

Epimeral plates: Posterior-inferior corner of epimeral plate 1 clearly pointed, 6–8 long setae on anterior distal corner; second and the third plate more sharply pointed; a row of short fine setae on posterior margin of all three plates; a combination of 3–4 setae and spines on distal sub-marginal area of 2nd and 3rd plate ( Fig. 9 D).

Telson: Length of the lobes about twice their widest width; distal margin with 1–2 long and robust spines and some 5–7 long setae; four groups of 3–6 long setae on dorsal surface of the lobes, occasionally accompanied by a long spine ( Fig. 7 J).

Urosomites: Urosome posterior dorsal do not have clear elevations, but each epimere is placed in a lower level than its anterior segment; dorsal armature consists of mainly some 5–6 long setae sometimes mixed with a spine on laterals and mid-dorsal ( Fig. 9 E).

Female. Female is smaller than male (7.5 mm).

Antenna 2 with no calceoli.

Propodus of gnathopod 1 without medial palmar spine, one long and one short palmar angle spine, 3 spines at posterior palmar margin.

Propodus of gnathopod 2 rectangular, palm is transverse and lack the medial palmar spine, but 2 palmar angle spines exist, a group of setae at medial palm.

Propodus of gnathopod 1 and 2 is smaller in respect to the other segments and the whole appendage than in males.

Proximal of gnathopod 1 and 2 bases are not wider than their distal part.

Basis of pereopods 5–7 less elongated than males, rather distinct convex angle at the middle of posterior margin in pereopod 6 and pereopod 7, protruding lobe more developed ( Fig. 10 A–C).

Uropod 3 with plumose setae on outer margin of endopodite only.

Epimeral plate 3 with fewer and shorter setae on anterior distal margin, epimeral plates 2 and 3 with 1–2 spines, while no setae on distal sub-margin, ( Fig. 10 D). Oostegite 1 is illustrated in Figure 10 E.

Cuticular ultrastructure. Polygons of head capsule cuticles show both types of L and S pore arrangements ( Fig. 6 B); L-types with line distances of 0.92–2.60 (Mean = 1.79, SD = 0.24); pore density in L-type polygons 94–123 pores per 25 µm2 (Mean = 108, SD = 12.45); S-type polygons without a special pattern ( Fig. 6 D), with density of 143–228 per 25 µm2 (Mean = 176, SD = 36.97).

Remarks. There are not many species that this species can be confused with. Some similarities with other species are discussed below.

G. l o e f f l e r i n. sp., distributed in south-east of the localities of G. s h i r a z i n u s shows some morphological similarities to it, including long setation of antenna 2 and shapes of pereopod bases and epimeral plates, but it differs from it in many characters, including longer eyes, antenna 1 spines, a shorter antennal gland cone, less groups of setae and spines on gnathopod 1 propodus, less (non-overlapping) number of D-setae on third segment of palp of mandible, non-developed pereopod 7 basis postero-distal lobe, setae on pereopod 7 basis postero-distal corner, shorter very short setae on pereopod 7 basis posterior margin, shorter setae on anterior margin of distal segments especially on pereopod 7, and longer and numerous setae on dorsal of urosomites.

G. crinicaudatus Stock et al., 1998 , has previously been reported from a close region in the Zagros Mountains. It looks like the new species in having a setiferous antenna 2 and telson, and a similar armature of gnathopod 1. However, there are several characters differentiating G. crinicaudatus from this new species, including a shorter eye, no groups of setae on lateral mid-length of peduncle segments 2 and 3 of antenna 1; shorter setae and no calceoli on antenna 2, four small accessory spines close to mid-palmar spine instead of 2 spines close to palmar angle spine, shorter setae and spines on pereopods 5–7, convex pereopod 7 basis posterior margin with more developed posterodistal lobe, weekly pointed postero-distal corner of epimeral plates 2–3, longer spines on the tip of telson, and longer setae on dorsal urosomal armature.

G. komareki is widely distributed in northern regions of the country. They have some similarities like an appearance of long setae on antenna 2, shape of basis in pereopods 5–7, and ratio of inner/outer ramus in uropod 3. On the other hand, several features make them distinctly different, among them are long eyes, shorter setae on antenna 2 flagellum, non-curled setae on antenna 2, having calceoli, 19–21 D-setae on palp of mandible, longer setae especially on basis but less dense setae on distal segments of pereopod 3, much more setose pereopod 4, very long setae on propodus-merus anterior margin of pereopods 5–7, having seate on posterior distal corner of pereopod 7, and much longer setae on uropod 3, telson, and posterior dorsal margin of urosome.

G. birsteini Karaman & Pinkster, 1977, distributed in Eastern Turkey and Kazakhstan has a similar setose antenna 2, pereopod 7 basis without postero-distal protruding lobe, and the urosome is not elevated. On the other hand, the gland cone in antenna 2 is longer and stays closely to the tip of 3rd segment, setae on pereopods 5–7 are quite short, epimeral plates are not pointed, and, most importantly, inner ramus of uropod 3 is very short and with very few setae ( Karaman & Pinkster, 1977; Fig. 31).

G. rambouseki S. Karaman, 1931 , has more similarities to this species, including the general setiferous impression, especially in antenna 2, pereopods 5–7, and dorsal of epimeres, shape of pereopod 5–6 basis and the setae on the postero-distal corner of pereopod 7 basis, and pointed postero-distal corner of epimeral plates 2–3, but it has clear differences like a small eye, more number of setae on second segment of mandibular palp and a group of A-setae on the third, lack of calceoli, having submarginal spines on propodus of gnathopod 2, and uropod 3 with shorter setae which all are simple ( Karaman & Pinkster, 1977; Fig. 32). The setouse character can also be seen in G. f r a t e r Karaman and Pinkster, 1977, which shows the similar shape of pereopods 5–7 basis and the postero-distal corner of pereopod 7, and has no elevation in its epimeres, while bears only spines on pereopods 5–7, very shorter setae on pereopod 3–4, telson, and epimeres, and no calceoli on antenna 2 ( Karaman & Pinkster, 1977; Fig. 34). Both of these two are specifically local species found exclusively in the Balkans.

G. qiani has the similar appearance of setose pereopods 5–7, not-developed pereopod 7 postero-inferior lobe, and the existence of postero-inferior corner setae, but shows actually almost all of its other features different, like a weekly setose antenna 1, moderately setose antenna 2, long gland cone, small eyes, moderately setose pereopod 3–4, short setae on an incompletely cleft telson, not pointed epimeral plates, and poor setation of entire uropod 3, according to Hou and Li (2002), Figures 1–5 .

Finally, G. translucidus shares some features with G. loeffleri like a moderately setose antenna 1, long setae on fourth and fifth peduncle segment of antenna 2, long setae on pereopods 5–7 (despite they look shorter), and the existance of few setae on pereopod 7 postero-inferior corner. On the other hand, it differs from the new species by having no eyes, longer antennal gland cone, short setae on pereopod 4, slightly developed postero-inferior lobe on pereopod 7, short setae and incomplete cleft on telson, slightly vs. moderately pointed epimeral plates, and scarce short setae on uropod 3 ( Hou et al., 2004; Figs. 1–4 ).

Ecology. Site description. This species inhabits a rather large spring-pool (ca. 20 40 m) and the first order stream originating from it located on the bottom of a hill. The stream continues to flow to a plain in southward direction; the water is used up in agriculture in most of the year. This location is 20 km NW of the city of Darab (220 km SE of Shiraz, capital of Fars Province). The spring bed is covered with coarse sand and large gravel, and some organic matter in between them. There are some trees on the stream margins, which amphipods can be most probably found among their free roots in water, as well as inside the decaying leaves trapped in them. There are two pools connected to the stream which are inhabited by some fish populations; amphipods were not found in these pools. Extensive areas at east and west of the spring are devoted to different Citrus orchards.

Ecological data. This spring is also located in a warm region, where the air temperature reaches to the highest value of some 48˚C in the early afternoon during some summer days (FRMD 2009b). At late morning, we measured the air temperature as 20˚C and 28˚C in winter and summer, respectively, while the measured water temperature had a constant value of 22.5˚C, both in winter and summer. Dissolved oxygen values were recorded at the very low amounts of 3.6 mg /dm3 and 3.2 mg / dm3. Other measured physical and chemical environmental parameters are presented in Table 1. Some records of water temperatures measured for additional localities are shown in Table 2.

G. shirazinus T (ºC) G. loeffleri . T (ºC) Barme-Delak 17.6 Aab Do-man-nim 15.3 Barme-shur 25 Aab Vohli 20.8 Barme-Tarkoshte 17.6 Atashkade 15

Kaftarak 18.5 Bahadoran river 17.1 Niriz 25 Bande Amir 18.5 Pire Bano 19.7 Fasa river 19.5 Pire Gheibi 20 Ghare Aghaj river 22

Se Barm 21 Nowbandegan 23.4 Oghlanghez 20.8 Pa-Naal 25

Sarve Nokhodi 11.9 Tang Aab 21

Figures

FIGURE 1. Map of the study area from Central to Southeast of Fars Province, Iran. Bold lines indicate borders of river catchments.

FIGURE 6. Micrographs of ultrastructural patterns on head region in Gammarus shirazinus n. sp. (A & C), and G. loeffleri n. sp. (B & D).

FIGURE 7. Gammarus loeffleri n. sp., holotype, ♂, 12.5 mm., from Cheshme Golabi spring, W of Darab. A: antenna 1, B: antenna 2, C: head capsule, D: mandible, E: palp of mandible, F: exopodite of maxilliped, G – H: left palp of maxilla 1, I: right palp of maxilla 1, and J: telson.

FIGURE 8. Gammarus loeffleri n. sp., holotype, ♂, 12.5 mm., from Cheshme Golabi spring, W of Darab. A: gnathopod 1, B: gnathopod 2, C: pereopod 3 and D: pereopod 4.

FIGURE 9. Gammarus loeffleri n. sp., holotype, ♂, 12.5 mm., from Cheshme Golabi spring, W of Darab. A: pereopod 5, B: pereopod 6, C: pereopod 7, D: urosomites, E: epimeral plates, and F: uropod 3.

FIGURE 10. Gammarus loeffleri n. sp., holotype, Ψ, 7.5 mm., from Cheshme Golabi spring, W of Darab. A: basis of pereopod 5, B: basis of pereopod 6, C: basis of pereopod 7, D: epimeral plates, and E: oostegite 1.