Watlingia chathamensis Gerken, 2010

Gerken, Sarah, 2018, The Lampropidae (Crustacea: Cumacea) of the World, Zootaxa 4428 (1), pp. 1-192 : 184-188

Watlingia chathamensis Gerken, 2010

( Figs 73–75 )

Watlingia chathamensis Gerken, 2010: 301–305 , figs 5–6.

Type material. Holotype: NIWA 45715 , subadult female . Paratype: NIWA 45716 , subadult female, dissected. Chatham Rise, 42.996 –42.991 °S , 178.996– 179.005°E.

Other material. 1 adult male, dissected, NIWA 94875 , 43.826 – 43.827 °S, 178.552– 178.55°E, 463 m, 13 November, 2011. 1 ovigerous female, 3 other individuals, NIWA 93176 ; 2 individuals, NIWA 95409 , 43.521 – 43.532 °S, 178.62– 178.632°W, 424–425 m, 18 April 2007. 3 individuals, NIWA 94507 ; 20 individuals, NIWA 95410 ; 2 individuals, NIWA 95411 ; 6 individuals, NIWA 95412 , 44.486 – 44.484 °S, 177.141– 177.146°E, 1235– 1239 m, 6 April 2007. 2 ovigerous females , 5 subadult females, 2 adult males, NIWA 70511 , 44.121 – 44.124 °S, 174.843– 174.845°E, 512–513 m, 4 April 2007. 3 individuals, NIWA 70513 ; 2 individuals, NIWA 70514 ; 1 individual, NIWA 70515 , 44.016 – 44.014 °S, 178.521– 178.518°E, 769–771 m, 7 April 2007. 4 individuals, NIWA 70512 , 43.836 – 43.833 °S, 176.709– 176.713°E, 478–479 m, 5 April 2007. 3 individuals, NIWA 70516 , 43.797 – 43.805 °S, 175.316– 175.315°E, 418–422 m, 27 April 2007 . 1 subadult female, NIWA 93171 ; 1 adult male, NIWA 93206 , 43.53 – 43.536°S, 178.505– 178.512°E, 346 m, 24 April 2007. 3 individuals, NIWA 95406 , 43.512 – 43.52°S, 176.18– 176.711°W, 196–218 m, 14 April 2007. 3 individuals, NIWA 70517 ; 1 adult male, NIWA 93210 ; 2 individuals, NIWA 95408 , 39.637 –- 39.646°S, 172.153– 172.152°E, 264–266 m, 7 June 2007 .

Diagnosis. Carapace with 1–3 pairs large, blunt tubercles, paired posterior dorsal swellings, medial posterior dorsal crest on the carapace in side view, telson with 4–5 pairs lateral setae.

Additional description. Ovigerous female, NIWA 93176, 4.3–5.0 mm. Carapace with 2 large tubercles, posterodorsal swelling, and median unpaired crest posteriorly, carapace with ventral fold towards midline; pseudorostral lobes 0.3 carapace length, blunt; eyelobe 0.1 carapace length, with lenses; carapace 1.8–2.0 length of pereonites together ( Fig. 73A, B ).

Adult male, NIWA 94875, 4.3 mm.

Carapace with 1 pair large tubercles, posterodorsal swelling, medial unpaired crest posteriorly, carapace with ventral fold towards midline; pseudorostral lobes 0.4 carapace length; eyelobe 0.1 carapace length, with lenses; carapace 1.6 length of pereonites together. Pereonite 5 with pair of penial lobes ( Fig. 73C ).

Antennule peduncle article 1 0.9 length of articles 2 and 3 together, unarmed; article 2 0.7 article 1 length, with short simple setae; article 3 0.6 article 2 length, with short simple setae; main flagellum of 5 articles, article 1 with cluster of slender aesthetascs, with short simple setae distally and 2 aesthetascs terminally; accessory flagellum equal to main flagellum length, of 3 articles, with simple setae distally ( Fig. 74A ).

Antenna extending to mid pleon; peduncle of 5 articles; articles 4–5 with ranks of setae, incompletely circling articles; flagellum 3.0 peduncle length, with short articles, each with 1–2 short setae ( Fig. 74B,C ).

Maxilliped 3 basis 1.0 all other articles together, with pappose setae medially, distal corner with 3 plumose setae; ischium 0.06 basis length, with plumose seta; merus 2.3 ischium length, with plumose seta; carpus 2.8 merus length, with with plumose and semiple setae medially; propodus 0.6 carpus length, with 3 plumose setae medially, simple seta laterally; dactylus 0.5 propodus length, with 4 simple setae terminally; exopod 1.0 basis length, basal article unarmed, flagellum with plumo-annulate setae ( Fig. 74D ).

Pereopod 1 basis 0.9 all other articles together, margin serrate, distal corner produced as 2 large teeth, with many simple setae, 2 plumose setae distally; ischium 0.04 basis length, unarmed; merus 4.0 ischium length, with 4 simple setae; carpus 2.6 merus length, with 3 simple setae; propodus 0.8 carpus length, with 2 simple setae; dactylus 0.9 propodus length, with 5 simple setae and simple seta terminally; exopod 0.8 basis length, basal article with short plumose setae, sflagellum with plumo-annulate setae ( Fig. 74E ).

Pereopod 2 basis 0.8 all other articles together, margins serrate, with simple setae; ischium 0.08 basis length, with simple seta; merus 2.2 ischium length, with 2 simple setae; carpus 2.5 merus length, with 5 simple setae; propodus 0.3 carpus length, with simple seta; dactylus 3.1 propodus length, with 5 simple setae and simple seta terminally; exopod 0.9 basis length, basal article with short plumose setae, flagellum with plumo-annulate setae ( Fig. 75A ).

Pereopod 3 basis 1.8 all other articles together, with simple setae; ischium 0.05 basis length, with stout simple seta; merus 2.7 ischium length, with simple seta; carpus 1.3 merus length, with 2 annulate setae; propodus 0.7 carpus length, with annulate seta; dactylus 0.6 propodus length, with 2 simple setae terminally; exopod 0.9 basis length, basal article with short plumose setae, flagellum with plumo-annulate setae ( Fig. 75B ).

Pereopod 4 basis 1.7 all other articles together, with short simple setae; ischium 0.07 basis length, with stout simple seta; merus 2.7 ischium length, uanrmed; carpus 0.9 merus length, with 2 annulate setae; propodus 0.7 carpus length, with annulate seta; dactylus 0.6 propodus length, with simple seta terminally; exopod 0.9 basis length, basal article with short plumose setae, flagellum with plumo-annulate setae ( Fig. 75C ).

Pereopod 5 basis 1.2 all other articles together, with simple setae; ischium 0.1 basis length, with simple seta; merus 1.7 ischium length, with simple seta; carpus 1.4 merus length, with 2 annulate setae; propodus 0.7 carpus length, with annulate seta; dactylus 0.4 propodus length, with 2 simple setae and simple seta terminally ( Fig. 75D ).

Pleopod 1 longest pleopod, basis with 2 plumose setae, rami with long plumo-annulate setae ( Fig. 75E ).

Pleopod 2 basis with 2 plumose setae, rami with long plumo-annulate setae ( Fig. 75F ).

Pleopod 3 shortest pleopod, basis with 2 plumose setae, rami with long plumo-annulate setae ( Fig. 75G ).

Telson 2.6 length of pleonite 6, lateral margins weakly serrate, with 5 simple setae with single subterminal setule laterally, 3 simple terminal setae, central seta much longer and stouter than outer pair ( Fig. 75H ).

Uropod peduncles 2.9 pleonite 6 length, 1.1 telson length, with 15–18 microserrate setae single subterminal setule medially. Uropod endopod of 2 articles, 0.8 peduncle length; article 1 with 4–8 setae with single subterminal setule medially, with curved simple seta laterally; article 2 0.9 article 1 length, with 5 simple setae with single subterminal setule medially, terminal simple seta 0.6 article length. Uropod exopod 0.9 length of endopod; article 1 0.2 length of article 1, unarmed; article 2 4.2 article 1 length, with 5–6 simple setae, terminal simple seta 0.7 article length ( Fig. 75H ).

Depth. 322–760 m

Distribution. Chatham Rise, New Zealand, 43°00– 44°30.1’S, 174°18.8’– 179°00’E.

Remarks. Watlingia cassis and W. chathamensis are very similar, but can be distinguished by the number of telson lateral setae and the carapace morphology. In W. cassis the telson bears 3 pairs of lateral setae; in W. chathamensis the telson bears 4–5 pairs of lateral setae. In W. cassis the carapace is without tubercles, while in W. chathamensis the carapace has 1–3 pairs of large tubercles, a pair of posterior dorsal swellings, and a median posterior crest. The posterior dorsal swellings are the most easily visible distinguishing characteristic, making a distinct dorsal hump in the side view, while the tubercles vary amongst individuals and may not be very obvious. In addition, W. chathamensis is larger than W. cassis , being closer to 5 mm in length while W. cassis is closer to 3 mm. In the samples examined, W. chathamensis is also much more commonly encountered than W. cassis , although they do co–occur.

Figures

FIGURE 73. Watlingia chathamensis. Ovigerous female NIWA 93176, A, side view. Paratype preparatory female NIWA 93176, B, dorsal view. Paratype adult male NIWA 93176, C, side view. Scale bars full body 1.0 mm.

FIGURE 74. Watlingia chathamensis. Adult male NIWA 94875, A, antennule; B, antenna; C, antenna; D, maxilliped 3; E, pereopod 1. Scale bars 0.1 mm.

FIGURE 75. Watlingia chathamesis. Adult male NIWA 94875, A, pereopod 2; B, pereopod 3; C, pereopod 4; D, pereopod 5; E, pleopod 1; F, pleopod 2; G, pleopod 3; H, telson and uropods. Scale bars 0.1 mm.