Nannoniscus magdae Kaiser & Janssen &  Mohrbeck 2021, SP. NOV.
Creators: name: Kaiser, Stefanie
name: Kihara, Terue Cristina
name: Brix, Saskia
name: Mohrbeck, Inga
name: Janssen, Annika
name: Jennings, Robert M.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Nannoniscidae
Nannoniscus
Nannoniscus magdae

description: NANNONISCUS MENOTI KAISER, JANSSEN & MOHRBECK, SP. NOV.
(FIGS 15–19)
Z o o b a n k r e g i s t r a t i o n: u r n: l s i d: z o o b a n k. org:act: 8BFC86F5-43FE-41AF-B49B-2793B2E7C3B8.
Type fixation: Holotype, ovigerous female, ZMH K-55354, 3.6 mm, designated here.
Material examined: Holotype: ovigerous female (Na27), 3.6 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 171 (start: 14°2’41’’N, 130°5’57’’W, 5024 m; end: 14°3’12’’N, 130°4’36’’W, 5017 m), date: 17/04/2015, ZMH K-55354.
Paratype: Preparatory female (Na18), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20 (start: 11°50’9’’N, 117°58’29’’W, 4093 m; end: 11°50’11’’N, 116°58’0’’W, 4093 m), date: 21/03/2015, ZMH K-55356; preparatory female (Na06), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 117 (start: 13°52’19’’N, 123°15’27’’W, 4498 m; end: 13°52’37’’N, 123°14’16’’W, 4521 m), date: 07/04/2015, ZMH K-55352; adult male (MA14_Iso272), CCZ, equatorial NE Pacific, KM14 expedition, RV Kilo Moana, EBS, station 38 (start: 11°47 52’’N, 117°30’31’’W, 4363 m; end: 11°48’3’’N, 117°29’45’’W, 4373 m), date: 13/05/2014, ZMH K-55350; preparatory female (Na42/Iso1120), APEI-6, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station APEI-6#1 (start: 19°27’52’’N, 120°1’31’’W, 4099 m; end: 120°0’58’’N, 120°0’58’’W, 4076 m), date: 20/03/2015, ZMH K-55355; preparatory female (NB12_Iso068), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 33 (start: 11°51’44’’N, 117°3’10’’W, 4133 m; end: 11°51’54’’N, 117°3’8’’W, 4133 m), date: 07/04/2012, ZMH K-55353; preparatory female (MA14_Iso352), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39 (start: 11°49’37’’N, 117°30’49’’W, 4361 m; end: 11°49’47’’N, 117°30’5’’W, 4343 m), date: 13/05/2014, ZMH K-55351; preparatory female (Na40/Iso1005), CCZ, equatorial NE Pacific, ABYSSLINE-2 expedition, RV Thomas G. Thompson, EBS, station S11 (start: 12°2’43.08’’N, 117°25’26’’W, 4223 m; end: 12°3’1.44’’N, 117°24’17’’W, 4235 m), date: 16/03/2015, ZMH K-55349; ovigerous female (MA13_ Iso453), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 90 (start: 11°49.718’N, 117°30.278’W, 4340 m; end: 11°49.906’N, 117°29.395’W, 4357 m), date: 03/05/2013, ZMH K-55348.
Etymology: The new species (menoti, Latin genitive, masculine) is named after Lenaick Menot, leader of the French party of the BIONOD expedition, for joint actions sieving and sorting the mud.
Distribution: This species has a wide distribution across the CCZ, being obtained from the eastern German, OMS, GSR and French (type locality) licence areas, as well as APEI-6 between 4076 and 5024 m depth.
Diagnosis: Body slender, length about 5.1 × pereonite 1 width; Mxp lateral margin with numerous small setae; Mxp epipodite reaching mid of palpal article 3; molar process of left Md with ≥ ten distal spines; Md incisor teeth rounded; pereonite 2 anterolateral tergites each with robust seta; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 15) short simple setae; Urp uniramous, not projecting beyond Plt posterior margin; male PlpI without hook-like projections distally.
Description of holotype and paratype female: Habitus (Figs 15D, 18), pereonites 2 and 3 damaged. Body length 5.1 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 15D, 18D, E), length 0.9 width. Anterior and lateral margins straight, posterior m a r g i n s l i g h t l y r o u n d e d. A n t e n n a e i n s e r t i n g frontolaterally in a deep fold. Pereonite 2 widest, pereonites 2–7 decreasing in width. Pereonite 1 width 0.8 pereonite 2 width, length 0.4 width. Pereonites 2 and 3 of similar length and width, length approximately 1.3 pereonite 1 length. Pereonite 4 longest, length 1.7 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, pereonites 3–4 each with a slender seta. Pereonite 5 width 0.9 pereonite 1 width, length 1.6 pereonite 1 length; pereonite 5 anterior margin slightly convex. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin convex. Plt length 0.2 body length, length 1.4 width; width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin straight. Urp length 0.2 Plt length, not projecting beyond posterior margin. AI described in situ from CLSM (Fig. 18A, E), from CLSM. Length 0.1 body length, with five articles. First article broadest, length twice width, with one broom seta distally. Second article as long as article 1, length 2.4 width, with two broom setae distally. Article 3 minute, length 0.2 article 1 length, as long as wide. Article 4 length 0.3 article 1 length, with a long distal projection reaching mid of article 5. Article 5 length 0.7 article 2 length, length 1.8 width. AII (Fig. 15A) length 0.4 body length, with six podomere and 11 flagellar articles. Podomere article 1 broken off, described from CLSM (Fig. 18A). Articles 1–4 short; article 3 with three simple setae and one small robust spine distally, article 4 with one simple seta distally. Article 5 length 1.5 articles 1–4 length, length approximately 5.8 width, with six simple setae laterally. Article 6 longest, length 1.1 article 5 length, length 6 width, with three simple setae laterally, with four broom setae of varying size and two long simple setae distally. Flagellar article 1 longest, conjoint with one setal position (fusion of 2 articles), length half podomere article 6 length, length 4.5 width, with two simple setae laterally. Flagellar articles 3–11 decreasing in length and width distally; each article with 1–3 simple setae distally. Article 11 with six long slender setae terminally. Md (Fig. 15B, C), palp of left and right Md broken off. Incisor process of rMd and lMd with four rounded teeth each. Lacinia mobilis of lMd with three teeth. Spine row of rMd with 12 robust spines, dentation decreasing proximally. Spine row of lMd with ten robust spines and several slender setae in between, dentation decreasing, seta size increasing proximally. Molar of lMd triangular, with ten serrate spines of varying size distally. MxII (Fig. 15E), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp (Fig. 15F), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 1 short, with several small setae laterally. Article 2 length 2.4 article 1 length, width 0.9 length, with several small setae laterally. Article 3 length 1.1 article 1 length, width 1.6 length, with four robust sensory setae (one broken off) and one somewhat longer simple seta distally. Article 4 length 1.4 article 1 length, width 0.3 length, with a distal projection reaching mid of article 5, with two slender setae distally. Article 5 length 0.8 article 1 length, width 0.3 length, with three slender setae of varying size terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis quadrangular, length 0.9 width. PI (Fig. 16B) basis length 3.4 width, one small simple seta ventrally. Ischium 0.6 basis length, length 2.6 width, with one long simple seta distodorsally. Merus length 0.6 ischium length, length 1.4 width, with two long simple setae distodorsally. Carpus length 2.2 merus length, length 3.7 width, with one simple seta distodorsally, with five unequally bifid setae and numerous small setae ventrally. Propodus length 0.6 carpus length, length 3 width, with one simple seta dorsally, with numerous small setae, membranously embedded, ventrally, with one simple seta distoventrally. Dactylus length about half propodus length, length 3.7 width, with three slender setae medially. Unguis length half dactylus length, with two long, slender setae underneath unguis. PII (Fig. 16C) basis length 3.8 width. Ischium length about half basis length, length 2.3 width, with one long simple seta distodorsally. Merus length 0.7 ischium length, length 1.5 width, with two simple setae of varying length distodorsally, with one simple seta ventrally, and one simple seta distoventrally. Carpus length 2.6 merus length, length 4.3 width, with seven unequally bifid setae ventrally increasing in size distally. Propodus length 0.6 carpus length, length 4 width, with one long simple seta distodorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 3.3 width, with numerous small setae, membranously embedded ventrally. Unguis length half dactylus length, with two long, slender setae underneath unguis. PIII (Fig. 16D) basis length 4.7 width, with one long robust simple seta distoventrally. Ischium 0.4 basis length, length 2.1 width, with one simple seta distodorsally. Merus length 0.9 ischium length, length 1.8 width, with one simple seta distodorsally, with one simple seta (broken off) distoventrally. Carpus length 2.5 merus length, length 5.4 width, with eight robust setae (three unequally bifid setae, five simple) ventrally. Propodus length 0.6 carpus length, length 4.8 width, with six long simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and two small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PIV (Fig. 16E) basis length 5.5 width, with three simple setae dorsally, with three simple setae ventrally. Ischium length half basis length, length 2.9 width, with one simple seta distodorsally, with one simple seta ventrally. Merus length 0.6 ischium length, length twice width, with one long simple seta distodorsally, with one long simple seta distoventrally. Carpus length 2.5 merus length, length 6.4 width, with five simple setae (underneath) dorsally, with nine slender simple setae ventrally, increasing in size distally. Propodus length 0.6 carpus length, length 4.8 width, with six simple setae (four broken off) dorsally, with numerous small setae, membranously embedded, and four small unequally bifid setae ventrally. Dactylus length 0.4 propodus length, length 6 width, with two simple setae medially, with numerous small setae ventrally. Unguis length 0.3 dactylus length, with two slender setae underneath unguis. PV (Fig. 16F) basis length 4.5 width, one long simple seta distodorsally. Ischium length 0.8 basis length, length 3.6 width, with two long simple setae dorsally. Merus length half ischium length, length 1.8 width, with two simple setae of varying size distodorsally, with one small simple seta distoventrally. Carpus length 2.1 merus length, length 3.4 width, with six long simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 2.9 width, with seven long simple setae (underneath) dorsally, with four long simple setae ventrally. Dactylus length half propodus length, length 3.5 width. Unguis length 0.7 dactylus length, with two setae of varying size underneath unguis. PVI (Fig. 16G) basis length 3.1 width, with one simple seta distoventrally. Ischium as long as basis, length 2.7 width, with one small simple seta ventrally. Merus length 0.4 ischium length, length 1.5 width, with two simple setae (one broken off) distodorsally, with one small simple seta ventrally. Carpus length 2.4 merus length, length 3.8 width, with one slender setae distodorsally, with three long simple setae ventrally. Propodus length 0.8 carpus length, length 5 width, with eight long setae dorsally, with two long setae distoventrally. Dactylus length half propodus length, length 5.3 width. Unguis length 0.8 dactylus length, with two slender seta underneath unguis. PVII (Fig. 16H) basis length 4.5 width. Ischium damaged, length 0.6 basis length, length 2.4 width. Merus length half ischium length, length 1.3 width. Carpus length 2.4 merus length, length 3.9 width, with eight long slender simple setae dorsally, with three simple setae dorsally, with one simple seta distodorsally, with three setae (two simple, one unequally bifid) of varying size ventrally. Propodus length 0.7 carpus length, length 4 width, with five long simple setae dorsally, with one simple seta ventrally, with one robust simple seta distoventrally. Dactylus length half propodus length, length 3.1 width. Unguis length 0.8 dactylus length, with two slender setae underneath unguis. Op (Fig. 15G), drawn in situ. Length 1.4 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins, with several (≥ 15) simple setae, setal size 0.1 Plt length. PlpIII (Fig. 15H) protopodite length 0.9 width, length 0.3 endopodite length. Exopodite half endopodite length, length 1.8 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.8 width, with two long plumose setae distally, distal margin rounded. PlpIV (Fig. 15I) protopodite rectangular, length 0.6 width, length 0.2 endopodite length. Exopodite slender, length 0.7 endopodite length, length 7.2 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 2.6 width, distal end tapering in an acute angle. PlpV (Fig. 15J) small oval lobe, without setation, about as long as pleopod 4 endopodite. Length 2.2 proximal width, width tapering towards distal end. Urp (Fig. 15K) uniramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite oval, length 1.4 width, with five simple setae of varying length laterally. Endopodite length 1.6 protopodite length, length 5.3 width, with one broom seta laterally, with three broom setae and four simple setae (three broken off) terminally.
Description of male paratype: Habitus (Figs 17A, 19). Body length 5.7 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Figs 17A, 19D, E), length 1.1 width. Anterior and lateral margins rounded, posterior margin almost straight. Antennae inserting frontolaterally in a deep fold. Pereonites 2–5 decreasing in width. Pereonite 1 length 0.3 width. Pereonite 2 widest, width 1.1 pereonite 1 width, length 2.1 pereonite 1 length. Pereonites 2–3 of similar length. Pereonites 4–7 of similar length, pereonite 4 length 1.9 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of perenonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3–4 each with simple seta. Pereonites 5–7 of similar width, width 0.8 pereonite 1 width. Pereonite 5 anterior margin straight. Pereonites 6–7 dorsomedially fused, pereonite 6 anterior margin straight. Plt 0.2 body length, length 1.4 width, width 0.7 pereonite 1 width; posterior margin strongly rounded, anterior margin slightly concave. Anus (Fig. 19B, F) covered by anus valves laterally. Urp inserting closely to the anus valves, length 0.2 Plt length, not projecting beyond posterior margin. PlpI (Figs 17B, 19B, F), length 3.2 proximal width. Distal projection width 0.4 proximal width, lateral margins slightly concave. Lateral lobes rounded, with five small setae inserting distally from each lateral lobe. Distal margins strongly rounded, with four simple setae of varying length each. PlpII (Fig. 17C), sympod length 2.5 width, outer margin rounded, with six long slender simple setae distally, with numerous small setae laterally; inner margin straight. Endopod inserting 0.3 from distal tip of sympod. Stylet length 0.6 sympod length, slightly curved, distal end not extending beyond distal tip of sympod. Exopod short and rounded, inserting 0.1 from distal tip of sympod. PlpIII (Fig. 17D), protopodite length 1.3 width, length half endopodite length. Exopodite half endopodite length, length 1.3 width, tapering in width distally, with numerous short simple setae laterally and one somewhat longer seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin rounded. PlpIV (Fig. 17E), protopodite rectangular, length 0.6 width, length 0.3 endopodite length. Exopodite slender, length 0.7 endopodite length, length 6.8 width, with several thin setules laterally (outer margin) and one long robust plumose seta distally. Endopodite length 1.8 width, distal margin rounded.
Remarks: The new species is distinct from most other species in the genus by possessing uniramous uropods. Besides N. menoti, only N. ovatus lacks a uropodal exopodite. The new species can be differentiated from N. ovatus as follows: body length 5.1 pereonite 1 width in female (vs. 4.7 in N. ovatus); Op posterior margin with ≥ 15 setae (vs. ≤ 9); Mxp lateral margin with numerous small setae (vs. Mxp lateral margin lacking setae); male PlpI without hook-like projections distally (vs. 3).
description: Published as part of Kaiser, Stefanie, Kihara, Terue Cristina, Brix, Saskia, Mohrbeck, Inga, Janssen, Annika & Jennings, Robert M., 2021, Species boundaries and phylogeographic patterns in new species of Nannoniscus (Janiroidea: Nannoniscidae) from the equatorial Pacific nodule province inferred from mtDNA and morphology, pp. 1020-1071 in Zoological Journal of the Linnean Society 193 on pages 1048-1055, DOI: 10.1093/zoolinnean/zlaa174, http://zenodo.org/record/5639160