Syrrhoe anneheleneae, Fuchs, Luisa, Coleman, Charles Oliver & Loerz, Anne-Nina, 2019

Fuchs, Luisa, Coleman, Charles Oliver & Loerz, Anne-Nina, 2019, The genus Syrrhoe (Crustacea, Amphipoda, Synopiidae) from the North Atlantic, Evolutionary Systematics 3 (1), pp. 85-108 : 85

Syrrhoe anneheleneae sp. nov. Figs 6, 7, 8, 9, 10, 11

Material examined.

Type material: 1 specimen, presumably subadult male, holotype, 9 mm, UNIS 2009 St. 12, AB 321, 79°1 ’2” N, 11°45 ’58” E, 232 m, 1.9.2009, RP sledge, ZMBN 112487; 5 paratypes, 2 females, 7.5 and 8 mm; 3 without sex determination, 7-8.7 mm, same as type locality, ZMBN 127920.

Additional material: 1 female, 2 specimens, without sex determination, Deutsche Expedition in das Nördliche Eismeer, 1898, St. 34, König Karls Land (Svalbard), leg. Römer & Schaudinn, ZMB 19834; 1 male, Deutsche Expedition in das Nördliche Eismeer, 1898, St. 47, Thymen Straße (Freeman Strait), 78°13'N 21°19'E, leg. Römer & Schaudinn, ZMB 19835; 3 specimens, without sex determination, UNIS 2015 St. 825, Svalbard, 78°8 ’55” N, 13°7 ’32” E, 243 m, 13.5.2015, RP sledge, ZMBN 112488; 3 specimens, without sex determination, UNIS 2009 St. 69, Svalbard, 81°1 ’46” N, 19°9 ’19” E, 174 m, 1.9.2009, RP sledge, ZMBN 112490; 1 specimen, without sex determination, UNIS 2009 St. 12 AB 321, Svalbard, 79°1 ’2” N, 11°45 ’58” E, 232 m, 1.9.2009, RP sledge, ZMBN 112486; 1 adult male, 10 mm, UNIS 2009, Adventfjord, 78°13 ’48” N, 15°33 ’36” E, 6.9.2009, RP sledge, ZMBN 112426; 1 specimen, without sex determination, UNIS 2015 St. 825, 78°8 ’55” N, 13°7 ’32” E, 243 m, 13.5.2015, RP sledge, ZMBN 112447; 3 males, 1 female, 2 specimens without sex determination, UNIS 2009 St. 50(2), Svalbard, 80° 6 ’31” N, 22°8 ’29” E, 216 m, 1.9.2009, RP sledge, ZMBN 112489; 12 males, 10 females, 211 without sex determination, UNIS 2015 St. 781, Kapp Mitra, 79°7 ’5” N, 11°5'E, 110 m, 8.5.2015, RP sledge, ZMBN 112451; 1 specimen ZMH-K 56185 (GenBank MK972331), 1 specimen ZMH-K 56186 (GenBank MK972330), 1 specimen ZMH-K 56187 (GenBank MK972327), East Iceland, Norwegian Sea, IceAGE st. 1219, 66°17.34'N, 12°20.8'W, 579 m, 22.09.2011.

Length ranges: females 7-9 mm, males 6-8 mm, without sex determination 4-9 mm.

Description

based on: male holotype, 9 mm, ZMBN 112487.

Head. Rostrum reaching half the length of article 1 of antenna 1; lateral cephalic lobe present, pointed; eyes present, large, oval, on dorsal part of head, unpigmented (Fig. 6a, b). Antenna 1 (Fig. 6e) article 1 with 2 teeth of different length, 1 large distally curved tooth and 1 shorter and straight tooth; article 2 without distomedial tooth, slightly shorter than article 1; article 3 somewhat shorter than article 2; accessory flagellum 3-articulate, surpassing 3rd flagellar article, 3rd article of accessory flagellum less than a quarter length of 1st accessory flagellar article; flagellum shorter than pereon, 14 articles. Antenna 2 (Fig. 7a) longer than antenna 1, not surpassing pereon; article 5 longest; flagellum 13-articulate, shorter than peduncle. Labrum (Fig. 6c) apically rounded, tapering distally. Mandible (Fig. 7b, c, d) incisor multidentate; left lacinia mobilis wide and multidentate; accessory setal row with 5 weakly denticulate setae; molar small, columnar, weakly triturative; palp article 1 smooth, shorter than half the length of article 2, article 2 with slender setae; article 3 half the length of article 1, with long 6 slender setae apically. Lower lip (Fig. 6d) with wide gap; inner lobes present, outer lobes apically setose; hypopharyngeal lobes wide. Maxilla 1 (Fig. 7e) inner plate with 8 plumose setae; outer plate with 11 apical robust setae; bifurcate setae present; palp article 2 outer margin smooth, with apical and medial setation. Maxilla 2 (Fig. 7f) inner plate width about 2 × outer plate, with row of facial setae. Maxilliped (Fig. 8 a–e) inner plate reaching 1st palp article, with 10 strong setae; outer plate distally and medially with simple robust setae; palp article 2 is 1.5 × the length of article 3; palp article 3 slightly inflated; article 4 weakly curved, with long unguis.

Pereon. Pereonite 1-6 dorsally, dorsolaterally and laterally smooth (Fig. 6a). Pereonite 7 posterior margin mid-dorsally serrate, with short point; posterolateral corner angular and not produced. Gnathopod 1 (Fig. 9a) coxa not tapering distally, apex strongly directed anteriorly; basis longer than carpus; carpus subrectangular, with smooth setae along the posterior margin; propodus palm transverse, defined by 1 serrate robust seta. Gnathopod 2 (Fig. 9b) coxa distally tapering; basis twice the length of carpus; carpus serrate setae along the posterior margin at ventral part; propodus palm nearly oblique, defined by 1 serrate robust setae; dactylus of gnathopod 2 well developed, unguis similar length to dactylus. Pereopod 3 (Fig. 10a) coxa anterodistal lobe present, obliquely produced, posterodistal lobe present, truncate, half the depth of the coxa, posterodistal margin with minute setae; basis width equal to breadth of ischium; ischium subquadrate, 1/4 of merus length; dactylus weakly curved. Pereopod 3-4 coxa pelagont. Pereopod 4 (Fig. 10b) coxa much shorter than coxa 3, lobate in shape, slightly curved posteriorly; ischium subquadrate, 1/4 of merus length; dactylus weakly curved. Pereopod 5-7 (Fig. 11 a–c) basis anterodistal corner weakly produced into a recurved hook, posterior margin strongly serrate. Pereopod 5-6 basis subovoid, expanded, posterodistal lobe weakly developed, not extending past ischium. Pereopod 7 basis ovate, posterodistal lobe well developed, rounded, extending below ischium.

Pleon. Pleonite 1-3 (Fig. 6a) dorsally round, without carination, posterior margin serrate and mid-dorsally with short point. Epimeron 1 posterior margin smooth, posterodistal corner weakly pointed. Epimeron 2 posterior margin smooth, posterodistal corner pointed. Epimeron 3 posterior margin serrate, posteroventral corner subquadrate.

Pleopod (Fig. 11d) rami similar length, 13 and 15 articles, all articles with setulated setae.

Urosomite 1 (Fig. 6a) mid-dorsal posterior and lateral margin serrate. Urosomite 2 (Fig. 6a) mid-dorsal posterior margin smooth. Urosomite 3 (Fig. 6a) mid-dorsal posterior margin smooth.

Uropod 1 (Fig. 10c) peduncle with long distal process, the process reaching half the length of outer ramus; inner ramus same length as peduncle; apical robust setae on tip of both rami present. Uropod 2 (Fig. 10d) apical robust setae on tip of outer ramus present, outer ramus half the length and half the with of inner ramus. Uropod 3 (Fig. 10d) length not exceeding uropods 1-2, outer ramus 2.5 × length of peduncle. Telson (Fig. 10f) almost as long as uropod 3 peduncle, 3 × as long as wide; with no setae along the lateral margin, with apical slender setae; lobes abutting, deeply cleft, more than 75%.

Distribution.

North Atlantic, 110-579 m.

Etymology.

Named for Dr. Anne Helene Tandberg, great amphipodologist and a friend of the authors, who organized the wonderful workshop in Bergen, where the new species was discovered.

Remarks.

Syrrhoe anneheleneae sp. nov. is rather similar to Syrrhoe crenulata . Both species have a narrow straight to excavate space between the dorsal serration and the serration of the epimeron 3. Syrrhoe anneheleneae sp. nov. has a serrate margin of urosomite 1 (vs. smooth in S. crenulata ) and in ethanol white eyes (vs. dark pigmented in S. crenulata ). A serration on urosomite 1 also occurs in S. papyracea Stebbing, 1888, but this species, only known from the type locality Culebra Island, Porto Rico ( Shoemaker 1935), differs in several respect from S. anneheleneae sp. nov.: head anteriorly produced; no eyes present; epimeral plates without posteromarginal serration and the palm of both gnathopods has an additional stout spine aside the serrate spine.