Orchestia montagui
Creators: name: Myers, Alan A.
name: Lowry, James K.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Talitridae
Orchestia
Orchestia montagui

description: Orchestia montagui (Audouin, 1826)   
(Figs 17–19)  
 Orchestia Montagui Audouin, 1826: 93, pl. ll, fig. 7.― Heller, 1866: 2, pl. 1, figs 3, 4.― Grube, 1866: 380, pl. 9, figs 1, 2.― Czerniavski, 1868: 118, pl. 8, figs 34-39.― Chevreux, 1893: 128, fig. 2.   
 Orchestia montagui.― Chevreux & Fage, 1925: 275, fig. 285.― Gurjanova, 1951: 802, fig. 557.― Bulycheva 1957: 155, fig. 56.―G. Karaman, 1970: 6, pls 1, 2.― Bellan-Santini, 1993: 749, fig. 513 (key).   
 Type locality. Egypt (According to Paula Martin-Lefevre, MNHN all of the Audouin material from Napoleaon’s Egyptian Campaign is lost).   
 Material studied. 3 males 2 females, Heraklion, Crete, Greece.   
 Description of adult male (20 mm).   
 Head. Eyes of moderate size. Antenna 1 short, scarcely reaching beyond peduncular article 4 of antenna 2; accessory flagellum absent; primary flagellum with 7 articles. Antenna 2 peduncular article 5 1.3 × length of peduncular article 4; flagellum longer than combined length of peduncular articles 4 and 5, with about 24 articles, final article cone shaped, with terminal cluster of imbricated setae. Labrum without epistome. Mandible left lacinia mobilis with 4 cusps. Maxilliped palp article 2 with distomedial lobe.   
 Pereon. Gnathopod 1 subchelate, coxa smaller than that of coxa 2; posterior margin of carpus and propodus each with lobe covered in palmate setae; propodus length to carpus length 1:1.5; propodus subtriangular; dactylus shorter than palm. Gnathopod 2 subchelate. basis length 3 × as long as broad; merus posterior margin with one short seta; propodus subovoid to subtriangular, distal width 2 × proximal width.; dactylus strongly falcate with strong proximal sinus on the posterior margin. Pereopods 3–7 cuspidactylate. Pereopods 3–4 dactylus stout. Peropod 4 dactylus thickened but without a notch on the posterior margin. Pereopod 5 basis subovoid. Pereopod 6 subequal in length with pereopod 7. Pereopod 7 basis posterior margin weakly serrate; merus strongly triangular, 2 × as wide distally as proximally; carpus strongly pyrifom, narrowing strongly distally, anterior and posterior margins strongly serrate; carpus and merus subequal in length; propodus 1.5 × length of carpus.   
 Pleon. Epimeron 3 posterior margin weakly crenulate.  Uropod 1 peduncle  much longer than subequal rami,  with distolateral robust seta. Uropod 2 peduncle a little longer than rami , rami subequal; exopod with 2 marginal robust setae; endopod with 3 marginal robust setae and 3 robust setae on inner face. Uropod 3 peduncle about 1.5 × as long as broad; ramus 1.5 × as long as broad about one third length of peduncle, outer margin with about 5 robust setae. Telson with about 7 marginal and apical robust setae.   
 Female (sexually dimorphic characters). Gnathopod 2 mitten-shaped, basis 1.5 × as long as broad, broadest proximally, anterior margin straight distally; carpus 1.7 × length of propodus. Pereopod 7 slender, merus and carpus unexpanded.   
 Habitat. Marine supralittoral living in banquette Posidonia and on mixed sand and coarse gravel beaches.   
 Remarks. Orchestia montagui differs from all other Orchestia species in the presence of a strong proximal sinus on the posterior margin of the male gnathopod 2 dactylus. It is also the only species in which the uropod 3 ramus is one third the length of the peduncle (subequal to about two thirds the length of the peduncle in other species). It also differs from all other species except O. mediterranea in the form of the carpus of the male pereopod 7 that is strongly scalloped or serrated on both margins. However, in O. mediterreanea, the posterior margin of the carpus narrows abruptly distally, whereas in O. montagui the carpus evenly narrows distally.   
 Distribution. An apparent Mediterranean and Black Sea endemic widely reported from a number of coasts, such as those of Spain (Chevreux & Fage 1925). France (Chevreux & Fage 1925, (Banyuls ru Mer? Charniaux- Legrand 1951), Karaman 1970). Italy (? Cecchini 1928,? Ruffo 1936, Brian 1939,? Giordani-Soika 1950, Bellan- Santini 1993).   
 Yugoslavia: (Heller 1866, Ruffo 1946, Krapp-Schickel 1969,? Karaman 1971).   
 Greece: Gournes, Heraklion, Crete, Greece (35°20’4”N 25°6’49”E) (Lowry & Fanini 2013), Rhodes (? Ruffo 1937, Bellan-Santini 1993, Karaman 1970, De Matthaeis et al. 1998).   
 Turkey: (Geldiay et al. 1971,? Karaman 1971).   
 Cyprus: (Kocataş, Kataðan & Benli 2001).   
 Egypt: (Audouin 1826).   
 Algeria: (Chevreux 1911, Krapp-Schickel 1969) Tunisia (Krapp-Schickel 1969).   
 Tunisia: (Chevreux 1911), Ghar El Melh Lagoon (Khemaissia, et al. 2017), Bizerte Lagon (? Jelassi & Nasri- Ammar 2012, 2013).   
 Black Sea: Lake Donuzlav (? Martynov 1931,? Miloslavskaja 1939,? Karaman 1970,? Sezgin et al. 2001).
description: Published as part of Myers, Alan A. & Lowry, James K., 2020, A revision of the genus Orchestia Leach, 1814 with the reinstatement of O. inaequalipes (K. H. Barnard, 1951), the designation of a neotype for Orchestia gammarellus (Pallas 1776) and the description of three new species (Crustacea: Amphipoda: Talitridae Talitrinae), pp. 201-250 in Zootaxa 4808 (2) on pages 224-226, DOI: 10.11646/zootaxa.4808.2.1, http://zenodo.org/record/3933375