Tanaidacea (Crustacea: Peracarida) of the northeast Atlantic: Chauliopleona Dojiri and Sieg, 1997 and Saurotipleona n. gen. from the ‘ Atlantic Margin’ Author Bird, Graham John text Journal of Natural History 2015 2015-02-28 49 25 1507 1547 journal article 21134 10.1080/00222933.2015.1005715 68d7cf72-3a99-4b8d-a9e5-244aed4e3b9e 1464-5262 3999694 Chauliopleona amdrupii ( Hansen 1913 ) ( Figures 2–4 , 18 ) Leptognathia Amdrupii Hansen, 1913: 81–82 , pl. VIII figs. 2a–c Leptognathia amdrupi : Nierstrasz 1913: 30 ; Stephensen 1932: 347 ; Stephensen 1937: 23 ; Stephensen 1943: 36 , 63; Just 1970: 24 ; else, see Sieg 1983 Chauliopleona amdrupii : Guerrero-Kommritz 2005: 1184–1187 , figs 3–4; else, see Anderson 2013 Diagnosis Cephalothorax 1.4 times longer than broad (ltb). Pereonites 1–6 all shorter than broad, with parallel lateral margins. Pleon shorter than cephalothorax, without posteriodorsal protuberances; pleonites 1–4 sternite with low recurved subrectangular process. Antennule article-1 (1.25 times) longer than rest of antennule. Maxilliped bases with short distal seta. Cheliped merus without inferior protuberance; carpus relatively slender, twice as long as broad, inferior shield shallow (aspect ratio ≈ 0.2), subtriangular, distal margin not angular; fixed finger with four teeth; dactylus superior margin smooth. Pereopods 1–3 basis with marginal setules; carpus and propodus inferior spinules fine to moderate; pereopods 2–3 carpus with distomedial seta. Pereopods 4–6 ischium with two short setae. Uropod exopod just over half the length of endopod segment-1; endopod slender,> three times longer than peduncle. Figure 2. Chauliopleona amdrupii . Non-ovigerous female, BIOICE Stn 3282: (A) habitus; (B) pleonal sternites, lateral; (C) antennule; (D) antenna; (E) pleopod endopod (setae very finely plumose, omitted for clarity; and following); (F) pleopod exopod; (G) uropod. Scale bar: 1 mm for A; 0.5 mm for B; 0.25 mm for C–G. Figure 3. Chauliopleona amdrupii . Non-ovigerous female, BIOICE Stn 3282: (A) labrum; (B–C) left mandible and molar; (D) right mandible; (E) maxillule; (F) maxilla; (G) maxilliped (one palp omitted); (H) cheliped. Scale bars: (i) 0.25 mm for A–G; (ii) 0.25 mm for H. Figure 4. Chauliopleona amdrupii . Non-ovigerous female, BIOICE Stn 3282: (A–F) pereopods 1–6 respectively. Scale bar 0.25 mm. Material examined One non-ov. ♀ , BIOICE Stn 2257; one non-ov. ♀ , BIOICE Stn 2697; one non-ov. ♀ , BIOICE Stn 2701; two non-ov. ♀♀ , BIOICE Stn 2849; five non-ov. ♀♀ , three prep. ♂♂ , BIOICE Stn 2853; eight non-ov. ♀♀ , three prep. ♂♂ , BIOICE Stn 3280; four non-ov. ♀♀ (one dissected on microslide), BIOICE Stn 3282; three non-ov. ♀♀ , BIOICE Stn 3518; one non-ov. ♀ , BIOICE Stn 3528; two non-ov. ♀♀ BIOICE Stn 3531; three non-ov. ♀♀ , one prep. ♂ , BIOICE Stn 3532 . Size Non-ovigerous female. Body length 2.44–3.64 mm , cf. 2.7 mm , Hansen (1913) , and 3.2 mm , Guerrero-Kommritz (2005) . Preparatory male: body length 2.96–3.16 mm . Distribution records from the AFEN, BIOICE and BIOFAR area Eleven records from the BIOICE survey: three from the Irminger Basin 1042–1209 m , eight from the Iceland Basin , 988–1840 m . All have positive bottom temperatures of 2.4–4.2°C, with various sediment types including ‘clay’, ‘silty sand’, and ‘shell-sand’ . Distribution elsewhere Originally described from Forsblad Fjord, East Greenland , 73–165 m ( Hansen 1913 ); other records are from Jörgen Brönlund Fjord, East Greenland , 160–180 m ( Just 1970 ), and the Greenland Sea, 188–191 m ( Guerrero-Kommritz 2005 ). Remarks This species of Chauliopleona is characterised by a relatively slender cheliped carpus that has a low-aspect ratio (shallow) sub-rectangular shield ( Figure 3H ) and a slightly recurved sternal process on pleonites 1–4 ( Figure 2C ). The basal setae of the maxilliped ( Figure 3G ) are also relatively short compared to those in C. armata and C. hastata . There is some discrepancy between the present specimens and the specimen illustrated by Guerrero-Kommritz (2005) in the size of the inferior propodal spinules on pereopods 1–3: his material, one specimen from the Greenland Sea, has robust spinules (also on the carpus), whereas the current material has both weak and moderate setules ( Figure 4A–C ). This better corresponds to Hansen’ s description of ‘second pair of legs [pereopod-1] without spinules on the posterior margin of sixth joint [propodus]’ ( Hansen 1913 , p. 81). The presence of a distomedial seta on the carpus of pereopods 2–3 is another possible distinguishing character from C. armata and C. hastata . This species is partly sympatric with C. armata and C. hastata in the Irminger Basin and its depth and geographic distributions indicate polar emergence.