Nannoniscus pedro, Kaiser, Brix & Kihara, 2021

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, Zoological Journal of the Linnean Society 193, pp. 1020-1071 : 1056-1061

publication ID	https://doi.org/ 10.1093/zoolinnean/zlaa174
publication LSID	lsid:zoobank.org:pub:A68FDF1F-2825-47D8-B9CE-FEB8432896DF
DOI	https://doi.org/10.5281/zenodo.14166091
persistent identifier	https://treatment.plazi.org/id/037E4E73-FFB4-FFBB-05CF-FE06FD64AEB9
treatment provided by	Plazi
scientific name	Nannoniscus pedro
status	sp. nov.

Treatment

NANNONISCUS PEDRO KAISER, BRIX & KIHARA View in CoL , SP. NOV.

( FIGS 20–22 View Figure 20 View Figure 21 View Figure 22 )

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: 820608B2-7BAA-43B1-8B40-3A5561937B8B.

Type fixation: Holotype, preparatory female, ZMH K-55358, 3.4 mm, designated here.

Material examined: Holotype: preparatory female (Na08), 3.4 mm, CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 133 (start: 13°50‘45’’N, 123°15’39’’W, 4516 m; end: 13°51’8’’N, 123°14’8’’W, 4427 m), date: 10/04/2015, ZMH K-55358.

Paratypes: Ovigerous female (Na11), 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-55362; preparatory female (Na04), 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-55361; preparatory female (Na05), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 20, ZMH K-55365; preparatory female (Na22), CCZ, equatorial NE Pacific, JPIO SO239 expedition, RV Sonne, EBS, station 24 (start: 11°51’19’’N, 117°1’30’’W, 4093 m; end: 11°51’31’’N, 116°58’0’’W, 4093 m), date: 22/03/2015, ZMH K-55363; preparatory female (NB12_Iso_290), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43 (start: 11°48’12’’N, 117°32’3’’W, 4358 m; end: 11°48’20’’N, 117°31’57’’W, 4358 m), date: 09/04/2012, ZMH K-55360; preparatory female (NB12_Iso_330), CCZ, equatorial NE Pacific, BIONOD expedition, RV L’Atalante, EBS, station 43, ZMH K-55364; preparatory female (MA13_Iso593), 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-55359; preparatory female (MA13_ Iso049), CCZ, equatorial NE Pacific, MA13 expedition, RV Kilo Moana, EBS, station 07 (start: 11°51.503’N, 117°01.205’W, 4131 m; end: 11°51.756’N, 117°00.171’W, 4121 m), date: 12/04/2013, ZMH K-55357; female, badly damaged (MA14_Iso319), 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-55367; male, badly damaged (MA14_Iso242), CCZ, equatorial NE Pacific, MA14 expedition, RV Kilo Moana, EBS, station 39, date: 13/05/2014, ZMH K-55366.

Etymology: The name is a noun in apposition, and dedicated to Pedro Martinez Arbizu, Principal Investigator of the JPIO EcoResponse expedition, for his drive and commitment to the exploration of the abyssal manganese nodule fauna.

Distribution: The species has a broad distribution across the CCZ, being collected from the eastern German, GSR (type locality) and French licence areas between 4093 and 5024 m depth.

Diagnosis: Body slender, length about 5.5 × pereonite 1 width; Mxp epipodite reaching mid of palpal article 3; Mxp lateral margin lacking fringe of setae; molar process of both Md each with only a few (≤ 5) distal spines; Md incisor teeth acute; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 without ventral spine; Op with a ventral posteriorly bent spine, posterior margin with numerous (≥ 21) long simple setae; Urp biramous, not projecting beyond Plt posterior margin; Urp endopodite length ≥ 3.2 exopodite length.

Description of holotype and paratype female: Habitus ( Figs 20A, B View Figure 20 , 22 View Figure 22 ), body length 5.5 pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax ( Figs 20A View Figure 20 , 22D–E View Figure 22 ), length 0.7 width. Anterior and posterior margins straight, lateral margin slightly rounded. Antennae inserting frontolaterally in a deep fold. Body abruptly flattening from pereonite 4 to 5. Pereonites 2–4 decreasing in width, pereonites 4–7 of similar width. Pereonite 1 length 0.3 width. Pereonite 1 and 2 of similar width, pereonite 2 length 1.7 pereonite 1 length. Pereonites 3 and 4 of similar length, length 1.2 pereonite 2. Pereonites 1–4 anterior margins frontally directed, anterolateral tergites of pereonite 2 each tipped with a robust seta, anterolateral tergites of pereonites 3 and 4 each with a simple seta. Pereonite 5 length 1.8 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, anterior margin of pereonite 6 convex. Plt length 0.2 body length, length 1.2 width, width 0.9 pereonite 1 width, posterior margin strongly rounded; anterior margin concave. Urp length 0.3 Plt length, not projecting beyond posterior margin. AI ( Fig. 20C View Figure 20 ), terminal article broken off, inferred from CLSM ( Fig. 22A, E View Figure 22 ). Length 0.1 body length, with five articles. First article circular and broadest, length 2.3 width. Second article length 0.7 article 1 length, length 1.8 width, with two simple setae distally. Article 3 minute, length 0.1 article 1 length, as long as wide. Article 4 length 0.1 article 2 length, with a long distal projection reaching mid of article 5, with one simple seta distally. Article 5 length 0.9 article 2 length, length 1.2 width, with one aestetasc terminally. AII ( Fig. 20D View Figure 20 ) length 0.4 body length, with six podomere and nine flagellar articles. Podomere articles 1–4 short. Article 5 longest, length 1.2 articles 1–4 length, length 5.4 width. Article 6 length 0.9 article 5 length, length 5.6 width. Flagellar article 1 longest, conjoint (fusion of three articles), length 0.6 podomere article 6 length, length 4.8 width. Flagellar articles 2–4 of similar length, length 0.2 flagellar article 1 length. Flagellar 5 article longest, length 0.3 flagellar article 1 length. Flagellar articles 1–9 decreasing in width distally, each article with 0–3 simple setae distally. Article 9 with seven long slender setae terminally. Md ( Fig. 21D, E View Figure 21 ), palp of right mandible damaged, of left mandible well developed, consisting of three articles almost reaching mid of incisor. Palpal article 2 of lMd length 1.2 article 1 length, with two simple setae laterally. Terminal article length about half article 2 length, tapering distally, with several small setae ventrally and two somewhat longer setae terminally. Incisor process of rMd with three acute teeth, incisor of lMd with six acute teeth and one subdistal tooth. Lacinia mobilis of lMd with three teeth. Spine row of rMd with ten robust spines of varying size and several slender setae in between; dentation decreasing proximally. Spine row of lMd with eight robust spines and several slender setae in between, dentation decreasing, spine size increasing proximally. Molar of rMd and lMd triangular; molar of rMd with four, of lMd with five long, serrate spines distally. MxI ( Fig. 21F View Figure 21 ) outer endite with 17 robust spine-like setae distally. Outer margin with several slender setae. Inner endite width 0.6 outer endite width, several fine setae distally, with two simple setae laterally. MxII ( Fig. 21G View Figure 21 ), outer margin of mesial endite with several setae of varying length, distal margin with numerous long setae of varying length. Mesial endite almost as long as lateral endite. Lateral endite and middle endite each with three strong setae distally. Mxp ( Fig. 21C View Figure 21 ), left and right Mxp connected by three retinacula. Epipodite smooth, triangular, slender, length 3.1 width, reaching mid of palpal article 3. Palpal article 2 width 0.9 length. Article 3 length 0.7 article 2 length, width 1.2 length, with seven robust sensory setae distally. Article 4 length 0.4 article 2 length, width half length. Article 5 length 0.4 article 2 length, width 0.2 length, with two slender setae terminally. Endite distal margin with some robust, dentate setae and several fine setae laterally. Basis length 1.5 width. PI ( Fig. 20E View Figure 20 ) basis length 4 width. Ischium about half basis length, length 2.3 width, with one long simple seta dorsally. Merus length 0.6 ischium length, length 1.4 width, with one long simple seta distodorsally. Carpus length twice merus length, length 3 width, with numerous small setae, membranously embedded, and three long unequally bifid setae in between ventrally. Propodus length 0.6 carpus length, length 2.7 width, with one slender simple seta distodorsally, with numerous small setae, membranously embedded, and two robust unequally bifid setae in between ventrally, with one simple seta distoventrally. Dactylus length 0.6 propodus length, length 4 width, with two slender setae medially, with numerous small setae, membranously embedded ventally. Unguis length 0.6 dactylus length, with two long, slender setae underneath unguis. PII ( Fig. 21H View Figure 21 ) basis length 4.4 width. Ischium length about half basis length, length 2.1 width, with two simple setae distodorsally. Merus length 0.8 ischium length, length 1.6 width, with three simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.1 merus length, length 4.2 width, with nine long slender simple setae (one broken off) ventrally. Propodus length 0.7 carpus length, length 4.3 width, with one simple seta distodorsally, with three simple setae ventrally. Dactylus length 0.4 propodus length, length 5.5 width, with three simple setae medially. Unguis length half dactylus length, with two slender setae underneath unguis. PIII ( Fig. 21I View Figure 21 ) basis length 4 width. Ischium length 0.6 basis length, length 1.7 width, with two simple setae of varying length (one underneath) distoventrally. Merus length 0.7 ischium length, length 1.8 width, with two simple setae of varying length distodorsally, with one long simple seta distoventrally. Carpus length 2.3 merus length, length 4.7 width, with nine long simple setae ventrally. Propodus length 0.7 carpus length. Dactylus length 0.3 propodus length, length 4.5 width. Unguis length 0.6 dactylus length, with two slender setae underneath unguis. PIV ( Fig. 21J View Figure 21 ) basis length 3.8 width. Ischium length 0.8 basis length, length 3.5 width. Merus length 0.6 ischium length, length 2.1 width. Carpus length 1.8 merus length, length 4.4 width, with seven long slender simple setae ventrally. Propodus length 0.9 carpus length, length 6.8 width, with two simple setae (underneath) dorsally, with two simple setae ventrally. Dactylus length 0.3 propodus length, length 3.5 width. Unguis damaged. PV ( Fig. 21K View Figure 21 ) basis length 4.6 width. Ischium length 0.8 basis length, length 3.6 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length 2.2 merus length, length 4.6 width, with one small simple seta distodorsally, with one slender simple seta medially, with five long, slender simple setae ventrally. Propodus length 0.7 carpus length, length 4.3 width, with nine long simple setae dorsally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. PVII ( Fig. 21L View Figure 21 ) basis length 5.2 width, with four long setae simple setae ventrally, with one simple seta distoventrally. Ischium length 0.7 basis length, length 2.9 width. Merus length half ischium length, length 1.7 width, with two simple setae distodorsally. Carpus length twice merus length, length 4.2 width, with one simple seta (one broken off) distodorsally, with four simple setae (two long, two broken off) ventrally. Propodus length 0.8 carpus length, length 5 width, with seven long simple setae dorsally, with one simple seta (broken off) distoventrally. Dactylus length 0.4 propodus length, length 6 width. Unguis length 0.7 dactylus length, ventral claw underneath. Op ( Fig. 20G View Figure 20 ) length 1.2 width, with a strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, with several (≥ 21) simple setae, setal size 0.1 Plt length. PlpIII ( Fig. 20H View Figure 20 ) protopodite length 0.9 width, length 0.4 endopodite length. Exopodite half endopodite length, length 1.7 width, tapering in width distally, with numerous short simple setae laterally, with one somewhat longer simple seta distally. Endopodite length 1.6 width, with three long plumose setae distally, distal margin strongly rounded. Urp ( Fig. 20I View Figure 20 ), biramous, length 0.25 Plt length, not projecting beyond Plt posterior margin. Protopodite damaged proximally, with one simple seta distally. Exopodite length 7.3 width, with two simple setae (one broken off) terminally. Endopodite length 3.2 exopodite length, length 6.4 width, with one simple seta laterally, with 6 setae (three long simple, three broken off) terminally.

Remarks: Nannoniscus pedro is most similar to species that are characterized by a slender body (body length ≥ 4.5 pereonite 1 width) as well as those possessing a uropodal exopodite and a ventral opercular spine. The new species most closely resembles N. hilario , but can be differentiated by the following characters: Mxp endopodite reaching mid of palpal article 3 (vs. distal third of palpal article 2 in N. hilario ); Md incisor teeth acute (vs. rounded); Urp endopodite length 3.2 exopodite length (vs. 6.3); Op posterior margin with ≥ 21 setae (vs. ≤ nine). Nannoniscus pedro is also similar to N. magdae , but differs from the latter species as follows: robust setae of anterolateral tergites of pereonite 2 present (vs. absent in N. magdae ); Md incisor teeth acute (vs. rounded). The new species can be distinguished from N. menziesi by the following characters: molar process of left and right Md with five and four distal spines, respectively (vs. 12 and 16 spines, respectively, in N. menziesi ); Urp endopodite length 3.2 exopodite length (vs. 5.4). Nannoniscus pedro differs from N. perunis as follows: Urp endopodite length 3.2 exopodite length (vs. 7.8). Finally, the new species can be distinguished from N. meteori by the following characters: Mxp epipodite length 3.1 width (vs. 6.4 in N. meteori ); Urp exopodite length 7.3 width (vs. 3.0); Urp endopodite length 6.4 width (vs. 3.2); Op posterior margin with ≥ 21 (vs. ≤ 15).