Atyaephyra thyamisensis, Christodoulou, Magdalini, Antoniou, Aglaia, Antonios Magoulas, & Athanasios Koukouras,, 2012

Christodoulou, Magdalini, Antoniou, Aglaia, Antonios Magoulas, & Athanasios Koukouras,, 2012, Revision of the freshwater genus Atyaephyra (Crustacea, Decapoda, Atyidae) based on morphological and molecular data, ZooKeys 229, pp. 53-110 : 71-73

Atyaephyra thyamisensis sp. n. Figs 7-8

Atyaephyra desmarestii . - Anastasiadou et al. 2004: 5-13, partim; Anastasiadou et al. 2011: 41-54, Figs 1-6.

Atyaephyra sp. n. 1. - Christodoulou et al. 2008: Fig. 4B.

Atyaephyra sp. n. 3. - Christodoulou et al. 2010: Fig. 2, partim.

Material examined.

Type material. Holotype: NHM 2012.1476, adult ovig. ♀ (CL 7.1 mm), Greece, Epirus, Thyamis River, 39°32.26'N, 20°09.76'E (Fig. 1, stn 76), among aquatic plants, 19.3.2005, coll. Ch. Anastasiadou; Allotype: NHM 2012.1477, adult ♂ (CL 5.3 mm), same data collection as holotype; Paratypes: NHM 2012.1478-1483, 4 ♀♀ (3 ovig.) (CL 6.0-6.8 mm) and 2 ♂♂ (CL 5.0-5.3 mm) same data collection as holotype. NHM 2012.1484-1485, 2 ♀ (CL 6.5-7.4 mm), Greece, Epirus, Louros River, 39°03.14'N, 20°46.26'E (Fig. 1, stn 72), among aquatic plants, 25.3.2012, coll. Ch. Anastasiadou. OUMNH.ZC 2012-08-001, 4 ♀♀ (2 ovig.) (CL 6.0-7.8 mm) and 2 ♂ (CL 5.2 mm) same data collection as holotype. SMF 43022, 4 ♀♀ (2 ovig.) (CL 5.8-7.1 mm) and 2 ♂♂ (CL 5.0-5.2 mm) same data collection as holotype. NHMW 25453, 4 ♀♀ (2 ovig.) (CL 5.5-7.5 mm) and 1 ♂♂ (CL 5.0 mm) same data collection as holotype

Non-type material.

Greece: 2 ♀♀ (CL 5.2-5.5 mm), NHMW 462, Corfu Island (Fig. 1, stn 75), 1.9.1937, coll. Stephanides ; 13 ♀♀ (1 ovig.) (CL 5.3-8.1 mm) and 8 ♂♂ (CL 5.2-6.2 mm), Epirus, Thyamis River (Fig. 1, stn 77), 20.5.2000 and 26.10.01, coll. Ch. Anastasiadou; 20 ♀♀ (15 ovig.) (CL 6.5-7.5 mm) and 3 ♂♂ (CL 5.0-5.7 mm), Epirus, Pamvotida Lake (Fig. 1, stn 78), 24.3.2006, coll. Ch. Anastasiadou; 20 ♀♀ (CL 5.0-7.0) and 8 ♂♂ (CL 5.0-5.5), Epirus, Ziros Lake (Fig. 1, stn 79), 28.10.2001, coll. Ch. Anastasiadou; 20 ♀♀ (CL 5.8-8.5 mm) and 4 ♂♂ (CL 5.2-6.4 mm), ZMAUTH D-334, Epirus, Filipiada, Louros River (Fig. 1, stn 80), 20.10.1977, coll. P. Economides; 15 ♀♀ (CL 5.5-8.0) and 6 ♂♂ (CL 5.0-6.0), Louros River (Fig. 1, stn 80), 28.10.2001, coll. Ch. Anastasiadou; 8 ovig. ♀♀ (CL 6.4-8.0 mm) and 6 ♂♂ (CL 5.3-6.2 mm), NHMW 465, Lefkada Island, Kaligoni, Vardas River (Fig. 1, stn 81), Aug.1929, coll. Beier; 3 ovig. ♀♀ (CL 7.3-8.0 mm) and 3 ♂♂ (CL 5.0-5.9 mm), NHMW 466, Lefkada Island, Kaligoni, Vardas River (Fig. 1, stn 81), 2.10.1932, coll. Beier.

Description.

Rostrum long, slender, dorsal margin straight or slightly curved in the middle and pointed upwards, shorter, equal to, or longer than scaphocerite, 6.0-9.50, most often (84% of the examined individuals) 6.33 to 8.76, × as long as high. 18-27 (18-24 in 91% of the individuals) pre orbital teeth on dorsal margin arranged up to tip of rostrum. 0-2, predominantly (84%) 1-2, post-orbital teeth. 4-10 teeth, most often (87%) 5-8, arranged on ventral margin of rostrum (Fig. 7A). Carapace smooth with pterygostomial angle bluntly produced (Fig. 7B). Pleuron of fifth abdominal segment pointed with an acute posterior angle (Fig. 7D). Telsonwith 5-8, mostly (97%) 5-7, pairs of dorsal spines arranged in curved fashion (Fig. 7E). Distal border of telson with 8-12, mostly (86%) 8-10, spines (4-6 pairs) arranged in fork-like pattern. Outermost pair of spines shortest, similar to dorsal spines, adjacent pair stronger terminating beyond (or along with) the finely setulose inner pairs (Figs 7 E–F). Basal segment of antennular peduncle with long stylocerite, with its tip reaching or overreaching the distal end of basal segment. Anterolateral lobe of basal segment short and round (Fig. 7H). Distal segment of antennular peduncle with 1-6, frequently (92%) 2-4, spines (Fig. 7G). Basal lower endite of maxilla densely covered with long simple setae arranged in 12-16 (13-15 in 80% of the individuals), oblique parallel rows. Endite of maxilla 1.84-2.24, mostly (93%) 1.89-2.05, × as long as basal lower endite (Fig. 8G). Basal endite of first maxilliped failing or reaching to distal end of exopod (Fig. 8F). Distal third of terminal segment of third maxilliped bearing 13-38 (19-30 in 88% of the individuals) mesial spines and one subdistal lateral spine near the base of larger terminal spine (Fig. 8H). Armature along flexor margin of dactylus of third and fourth pereiopod consisting of 6-9 (7-9 in 97% of the individuals) and 6-10 (7-9 in 97% of the individuals) spines respectively (Figs 8B, 8D). Merus of third and fourth pereiopod with 3-7 (4-6 in 93% of the individuals) and 2-6 (4-5 in 96% of the individuals) spines respectively (Figs 8A, 8C). Dactylus of fifth pereiopod with 28-43, usually (82%) 32-40, spines arranged in comb-like fashion on flexor margin (Fig. 8E). Endopod of first male pleopod expanded proximally and with a distal portion elongated (ribbon shaped) and tapering. Endopod with 14-21 spines arranged on a slightly or strongly curved inner margin and 12-18 setae arranged on outer margin (Fig. 8I). 172-465 eggs of 0.60-0.7 × 0.40-0.45 mm in size.

Size.

Atyaephyra thyamisensis sp. n. is a large sized species with a maximum carapace length of 6.4 mm in ♂♂, 8.0 mm in ♀♀ and 8.1 mm in ovig. ♀♀.

Molecular characters.

Atyaephyra thyamisensis sp. n. is different from all the other species of Atyaephyra by molecular characters, as shown by the phylogenetic analysis of mtDNA COI sequences. The one haplotype found was unique in the genus. Furthermore, it differs from all the other species in the following nucleotide positions in the COI gene of Atyaephyra desmarestii specimen Dour1, position 172: cytosine (C), position 207: cytosine (C), position 249: guanine (G), position 258: cytosine (C), position 324: guanine (G), position 348: guanine (G) and position 387: cytosine (C).

Etymology:

Atyaephyra thyamisensis sp. n. is named after the Thyamis River, Greece, the type locality.

Distribution.

Atyaephyra thyamisensis sp. n. is found in fresh water habitats of North-west Greece as well as in the islands Corfu and Lefkada (see material examined and Fig. 1).

Remarks: Atyaephyra thyamisensis can be discriminated from Atyaephyra stankoi by the presence of a sharply protruding pterygostomial angle (Fig. 7B). It should be noted that this character has been observed to be missing from one side (either the left or the right) in some very large sized individuals (Fig. 7C). This character is shared by Atyaephyra orientalis (present in some populations) along with the presence of numerous spines (10-38) on terminal segment of third maxilliped (Figs 4H, 8H) and the presence of fewer rows of setae (12-16) on basal lower endite of maxilla (Figs 4G, 8G). The two species can be distinguished by the presence of a rounded antennular lobe in Atyaephyra thyamisensis (Figs 7 G–H) (vs. pointed in Atyaephyra orientalis ; Figs 3 G–I). Further, Atyaephyra thyamisensis can be distinguished by the slightly or strongly curved endopod of first male pleopod having its distal part always elongated and tapering (ribbon shaped; Fig. 8I) (vs. strongly curved and distally stout and not tapering in Atyaephyra orientalis ; Fig. 4I). Atyaephyra thyamisensis can be separated easily from the remaining three species of Atyaephyra by the presence of numerous mesial spines (13-38; Fig. 8H) on terminal segment of third maxilliped (vs. 0-8 mesial spinesin Atyaephyra desmarestii , Atyaephyra strymonensis , Atyaephyra acheronensis and Atyaephyra tuerkayi ; Figs 10H, 12H, 14H).