Cryptorchestia garbinii Ruffo, Tarocco & Latella, 2014

Davolos, Domenico, Matthaeis, Elvira De, Latella, Leonardo, Tarocco, Marco, Oezbek, Murat & Vonk, Ronald, 2018, On the molecular and morphological evolution of continental and insular Cryptorchestia species, with an additional description of C. garbinii (Talitridae), ZooKeys 783, pp. 37-54 : 37

Cryptorchestia garbinii Ruffo, Tarocco & Latella, 2014 Figs 3, 4, 5, 6, 7

Localities.

The specimens of C. garbinii reported from Turkey were distributed in Lake Iznik (Bursa Province), Lake Sapanca (Sakarya province), and in a stream near Kiyiköy (Kirklareli province) (Fig. 1).

Material used for morphological description.

One male of 12 mm, one female of 13 mm from Iznik Lake, coordinates 40°24'20.39"-29°41'52.75", date 28 VIII 2003; one male of 16 mm from Sapanca Lake, 40°42'16.74"-30°11'36.14", 24 VIII 2003. Additional specimens: 6 males, 4 females of Lake Iznik; 6 males, 4 females from Lake Sapanca (Table 1).

Diagnosis.

Talitridae , with antenna I shorter than the combined peduncle segments of antenna II; accessory flagellum absent; mandible without palp, left mandible with 5-dentate lacinia mobilis; maxilla I with nine setae on inner lobe; maxilliped palp article IV reduced; gnathopod I male with a small, partially transparent lobe on merus; pereopod IV with bulged inner margin of dactylus; pereopods 3-7 cuspidactylate; telson variable in shape, longer than wide in holotype from Lake Garda, wider than long in the Turkish populations.

Additional description.

Based on adult males with an average length of 14.58 mm (Table 1). Head.Antenna I (Fig. 3A) flagellum with five to seven articles. Antenna II (Fig. 3B) little shorter than half of the body length, peduncle article V longer than article IV, flagellum with 16-21 articles. Labrum (Fig. 3C) and labium (Fig. 3D) with very fine setules on anterior margin. Mandible (Fig. 3E, F) left with 5-dentate lacinia mobilis and 5-dentate pars incisiva, right mandible with multi-teethed lacinia mobilis. Maxilla I (Fig. 3G) with nine robust and crenelated setae on inner lobe. Maxilla II (Fig. 3H) with numerous apical setae, a long and finely pinnate seta on inner margin of inner lobe. Maxilliped (Figs 3I, 7C) basal lobe with three blunt teeth on anterior margin, axial margin lined with robust setae armed with setules; palp article IV reduced, but clearly visible.

Coxae. Coxal plate I (Fig. 4B) with irregularly placed larger and smaller setae on distal margin. Coxal plates II-IV wider than deep (Figs 3J, 5A, B), plate V elongated, bilobate (Fig. 5C), plates VI and VII smaller (Fig. 5D, E).

Pereon.Gnathopod I male (Figs 4A, B, 7B) sexually dimorphic, subchelate; merus with small, partly transparent lobe on posterior margin; carpus with four or more setae on posterior margin, lobe present; propodus with sinoid palm in the 12 mm, but straight in 16 mm individual, and with a transparent lobe covering almost the entire palmar margin; dactylus as long as anterolateral margin of the propodus. Gnathopod II (Figs 3J, 7A), subchelate; propodus oviform, palmar margin with shallow sinus in the anterodistal part; Pereopods 3-4 (Figs 5A, B, 7D) with pereopod III slightly longer; dactylus in pereopod IV with bulged inner margin. Pereopod V (Fig. 5C) with wide basis; merus and carpus with pairs of robust setae on both sides of distal margins. Pereopods III–VII cuspidactylate. Pereopod VI (Fig. 5D) shorter than pereopod VII; coxa with small inside lobe; basis wide; carpus of same length as propodus. Pereopod VII (Fig. 5E) basis wide with distinct, rounded posterodistal lobe; propodus longer than carpus.

Pleon.Epimeral plates (Fig. VIA, B), posterior margins weakly crenulate. Pleopods I-III (Fig. 6B) well developed, biramous; rami with slender setae; inner ramus slightly shorter than outer. Uropod I (Fig. 6C) with two rows of seven axial setae on peduncle; rami of equal length, with three to four apical setae (of which one on the inner ramus longer than others). Uropod II (Fig. 6D) peduncle with one row of four axial setae; rami of equal length, outer ramus with four apical setae of which two small, inner ramus with two apical setae. Uropod III (Figs 6E, 7E) peduncle with three to four distolateral setae, ramus with four apical setae of which one long, and two additional lateral setae in 16 mm individual. Telson (Figs 6F, G, 7F) wider than long, dorsal midline cleft, five to eight marginal and distal setae per lobe of which two regular on the apex.

Female. Based on adult females with an average length of 13.10 mm (Table 1). Antenna I short, 1.22 mm length in average, flagellum with four articles. Antenna II long, 4.21 mm in average. Gnathopod I (Fig. 4C) subchelate; coxal plate lower margin with irregularly placed prominent setae; basis rectangular with several short setae; carpus with one robust and long seta between several smaller on lower margin; propodus with three bundled groups on the palmar margin; dactylus with unguis longer than palm. Gnathopod II (Fig. 4D), basis large, with strongly curved anterolateral margin; merus with lobe or patch with fine structures resembling a rasp surface; carpus and propodus expanded, with lateral lobes, propodus with rounded frontal margin and small claw.

Remarks.

The specimens from the Turkish lakes Iznik and Sapanca show some slight morphological differences compared to the Lake Garda (type locality) specimens. We interpret this as intraspecific variation. The lobe on the merus of the first gnathopod is smaller in the 12 mm male (Fig. 4B) than in the 16 mm male, especially when the twist in the carpus-propodus part relative to the merus forces the gnathopod to appear in an angle on a mounting slide. The feature is clearer in SEM photographs where it shows a rugose patch.

The specimens from Turkey were also compared to the geographically more adjacent freshwater species C. ruffoi from the island of Rhodes, Greece, to C. cavimana from Cyprus, and to C. kosswigi (Ruffo, 1949) from the Hatay province in southern Turkey. Differences are: a small lobe on merus of gnathopod I in male (large in C. ruffoi , not mentioned as present in C. cavimana by Heller (1865) in his German text but vaguely present in the figures); antenna I with 5-7 segmented flagellum (5-6 in C. garbinii of Lake Garda, four in C. ruffoi , six in C. cavimana , six in C. kosswigi ); pereopods V–VII with wide bases and of short and stubby appearance (less wide in C. garbinii of Lake Garda, C. ruffoi and C. cavimana , broad in C. kosswigi but here the other segments are long and slender); gnathopod II female with very broad and rounded basis (less in C. ruffoi , not mentioned in C. cavimana , but prominently present in the C. cavimana that was partly redescribed from the British Isles ( Lincoln 1979), and present to a lesser extent in C. kosswigi ); pereopod IV with clear bulge on dactylus (not mentioned in C. garbinii of Garda lake, not present in C. ruffoi and not mentioned in C. cavimana , present in C. kosswigi ). We consider these differences as interspecific variation of morphological features.