Oedicerina claudei, 2022

Jażdżewska, Anna M., Brandt, Angelika, Arbizu, Pedro Martínez & Vink, Annemiek, 2022, Exploring the diversity of the deep sea-four new species of the amphipod genus Oedicerina described using morphological and molecular methods, Zoological Journal of the Linnean Society 194, pp. 181-225 : 208-213

publication ID	https://doi.org/ 10.1093/zoolinnean/zlab032
publication LSID	lsid:zoobank.org:pub:01794248-7D36-42DC-B1FD-2A61FBEEB577L
DOI	https://doi.org/10.5281/zenodo.5799351
persistent identifier	https://treatment.plazi.org/id/F5496436-FFF9-3A34-13EC-86FAFBC5E450
treatment provided by	Plazi
scientific name	Oedicerina claudei
status

Treatment

OEDICERINA CLAUDEI JAżDżEWSKA View in CoL , SP. NOV.

( FIGS 19–23 View Figure 19 View Figure 20 View Figure 21 View Figure 22 View Figure 23 )

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: D1CB7EA5-FC38-406F-A101-BC5EBE7E1762.

Type material

Holotype: Juvenile, 4.5 mm, body remnants and two slides with appendages, SMF-56781 , St. AKL-71-1-9, 46°05.037’ N, 146°00.465’ E- 46°08.727’ N, 146°00.227’ E; 3307– 3307 m, 10 July 2015, leg. Marina V. Malyutina GoogleMaps .

The registered type material is deposited in the Senckenberg Museum (Frankfurt, Germany).

Type locality: Sea of Okhotsk, St. AKL-71-1-9, 46°05.037’ N, 146°00.465’ E- 46°08.727’ N, 146°00.227’ E; 3307– 3307 m.

Etymology: The species is named for Dr. Claude De Broyer, a great friend and one of the first author’s scientific mentors and renowned specialist in amphipod taxonomy, diversity and ecology.

Description: Based on juvenile, 4.5 mm, St. AKL-71-1-9. Head ( Fig. 19 View Figure 19 ): longer than deep, longer than pereonites 1–4 combined; no eyes or ocular pigment visible; rostrum deflexed, the angle between head dorsal margin and rostrum margin almost 90 °, rostrum reaching the end of first article of peduncle of antenna 1; interantennal lobe indistinct. Antenna 1 ( Fig. 20 View Figure 20 ): length ratios of peduncle articles 1–3 1:0.7:0.4, peduncle article 1 laterally acutely produced; flagellum 5-articulate, first article as long as article 3 of peduncle; accessory flagellum 1-articulate, minute, slender, length 0.2 × first flagellum article; peduncle and flagellum sparsely setose. Antenna 2 ( Fig. 20 View Figure 20 , considerably damaged): length of peduncle article 4 1.5 × article 5. Upper lip (labrum) ( Fig. 20 View Figure 20 ): wider than long, rounded apically, with fine setules laterally. Mandible ( Fig. 20 View Figure 20 ): incisor margins with five teeth; left lacinia mobilis four-cusped; right lacinia mobilis narrower slightly cuspidate; accessory spine rows with five serrate setae; molar columnar, strongly triturative, denticulate, with one associated seta; palp 3-articulate, article 1 short, article 2 1.1 × longer than article 3, with four posterodistal setae, article 3 slightly tapering distally, anterior margin with two setae, posterior margin with two setae, three setae at apex. Lower lip ( Fig. 20 View Figure 20 ): outer lobes broadly rounded, mandibular lobes narrow; inner lobes large, separate. Maxilla 1 ( Fig. 20 View Figure 20 ): inner plate oval, with two distal setae; outer plate with eight acute setal-teeth (three with bifurcate tips); palp 2-articulate, longer than outer plate, slender, rounded apically, article 1 short, length 0.2 × article 2, article 2 with five or six apical/subapical setae and one long, lateral setae. Maxilla 2 ( Fig. 20 View Figure 20 ): left—plates subequal in length, right—inner plate shorter than outer, inner plate width about 1.1 × outer, with setae and spines apically and subapically, fine setules along inner margin; outer plate rounded with apical spines and setae, outer margin with fine setules. Maxilliped ( Fig. 21 View Figure 21 ): inner plate subrectangular, reaching about 0.3 × basal article of palp, apical margin with six slender spines; outer plate slender and slightly curved, long, reaching 0.4 × length of palp article 2, apical and medial margins with setae and small spines; palp 4-articulate, strong; article 1 tapering distally; article 2 triangular, widest at 0.6 × length, setose medially; article 3 expanded mediodistally, slightly produced along article 4; article 4 strong, slightly curved; length ratios of articles 1–4 1:1.9:0.7:1.3.

Pereon. Pereonite 1 ( Fig. 19 View Figure 19 ) twice as long as pereonite 2, pereonite 3 longer than 2, pereonites 4–5 subequal in length, longer than pereonites 1–3, pereonites 6–7 of the same length, longer than all preceding segments. Gnathopod 1 ( Figs 19 View Figure 19 , 21 View Figure 21 ): coxa subtriangular, anterodistal corner bluntly rounded, posterodistal corner rectangular, ventral margin naked, width to depth ratio 1:0.8; basis straight, slightly expanded distally, distal half of anterior margin with row of long setae, sparse setae on the surface; merus, posterodistal lobe subquadrate, moderately setose; carpus strongly expanded, anterior margin with five setae along distal half, posterior lobe subacute with setae along posterior and distal margins; propodus subchelate, triangular, strongly widening distally, anterior margin moderately setose, palm longer than hind margin, transverse, strongly convex, margin crenate, with fine denticulations, with medial spines and lateral row of submarginal setules, palmar corner subrectangular with one spine; dactylus curved, longer than palm. Gnathopod 2 ( Figs 19 View Figure 19 , 21 View Figure 21 ): coxa narrow, slightly tapering distally, width 0.4 × depth, apex rounded, ventral margin naked; basis straight, 16 long setae forming circular patch anterodistally, single moderately long, delicately plumose seta at posterior margin; merus, posterodistal lobe rounded, moderately setose; carpus strongly expanded, wider than propodus, anterior margin with four setae (some delicately plumose), posterodistal lobe subacute, extending palmar corner of propodus, distal margin oblique armed with a row of spines, posterior margin with moderately long setae; propodus shorter than carpus, subchelate, triangular, strongly widening distally, anterior margin with eight long setae regularly placed, palm shorter than hind margin, transverse, convex, margin crenate, with fine denticulations, with medial spines and lateral row of submarginal setules, palmar corner subrectangular with one spine; dactylus curved, slightly longer than palm. Pereopod 3 ( Figs 19 View Figure 19 , 22 View Figure 22 ): coxa subrectangular, wider and deeper than coxa 2, ventral margin naked; basis shorter than coxa, narrow, length 3.1 × width, anterior and posterior margins with some long, delicately plumose setae; merus expanded distally, one group of setae anterodistally and two groups of setae posteriorly; carpus broad, length 1.2 × merus, posteriorly armed with long setae; propodus length 0.8 × carpus, with six long setae anterodistally and seven long setae along posterior margin; dactylus stout, longer than propodus (1.2 × propodus). Pereopod 4 ( Figs 19 View Figure 19 , 22 View Figure 22 ): coxa wider than deep, anterior margin strongly convex, extending distally, coxa the widest almost at 2/3 of its depth, ventral margin naked, posteroventral lobe huge, blunt, (width to depth ratio of the lobe 1:0.9), posterior margin deeply excavated; basis long and narrow, length 3.5 × width, anterior margin with four long, delicately plumose setae, posterior margin with one long, delicately plumose setae, short seta at posterodistal corner; merus expanded, a few setae at anterior margin, one short seta at posterior margin, group of long setae at posterodistal corner; carpus expanded, length 0.8 × merus, five setae at anterodistal corner, posterior margin armed with 11 long and moderately long setae; propodus narrow, length 0.5 × carpus, moderately setose at anterior and posterior margins; dactylus stout, longer than propodus (1.9 × propodus). Pereopod 5 ( Fig. 22 View Figure 22 ): right—coxa about as deep as coxa 4, bilobed, posterior lobe expanded ventrally, ventral margin straight, naked, anterior lobe 0.5 × depth of posterior lobe; basis narrow, length 4.1 × width, five long, delicately plumose setae at anterior margin; merus as long as basis, with three groups of moderately long plumose setae along anterior margin, seven setae at anterodistal corner, two setae at posterior margin and a group of four setae at posterodistal corner; carpusdactylus broken off; left—coxa about as deep as coxa 4, bilobed, posterior lobe partially damaged; basis narrow, length 2.5 × width, two long, delicately plumose setae at anterior margin, two long setae at the surface (one delicately plumose); merus 1.1 × basis, with three groups of moderately long setae along anterior margin, four setae at anterodistal corner, two setae at posterior margin; carpus length 0.5 × merus, with five setae anterodistally; propodus length 1.6 × carpus length, with three setae anterodistally; dactylus stout, longer than propodus (1.2 × propodus length). Pereopod 6 ( Fig. 22 View Figure 22 ): coxa bilobed but anterior lobe very small, posterior lobe long, distal margin slightly convex; basis narrow, length 3.9 × width, anterior margin with seven long, delicately plumose setae along distal half, posterior margin with five long, delicately plumose setae along distal half; merus length 0.7 × basis, three rows of setae anteriorly, two rows of setae posteriorly; carpusdactylus broken off. Pereopod 7 ( Fig. 22 View Figure 22 ): coxa wider than deep, rounded posteriorly; basis ovate, length 1.5 × width, widest in the mid-length, tapering distally, anterior margin strongly convex, two short spines at anterodistal corner, posterior margin slightly oblique in distal half, smooth, posterodistal lobe nearly as long as ischium; merus length 1.2 × basis with groups of setae both anteriorly and posteriorly (some setae broken); carpus-dactylus broken off.

Pleon. Pleonite 1 ( Fig. 19 View Figure 19 ) produced posteriorly, pleonites 2–3 with distinct mid-dorsal, posteriorly directed teeth. Epimera: 1 and 3 evenly rounded, epimeron 2 posterior margin convex, posterodistal corner subquadrate. Pleopods [pleopod 2 ( Fig. 23 View Figure 23 )]: powerful, peduncles and rami long.

Urosome. Urosomite 1 ( Fig. 19 View Figure 19 ) longest; urosomite 3 longer than 2. Uropods ( Fig. 23 View Figure 23 ): Uropod 1: peduncle length 1.1 × inner ramus, margins with some short setae; inner ramus 1.4 × length of outer ramus, rami with sparse setae. Uropod 2: shorter than uropod 1, peduncle length 0.9 × inner ramus, with some short setae; inner ramus 1.2 × length of outer ramus, rami with sparse setae. Uropod 3: peduncle short, peduncle length 0.4 × inner ramus; inner ramus with short spines along distal half of lateral margins; outer ramus damaged. Telson: ( Fig. 23 View Figure 23 ) short, length 1.7 × width, cleft 40%, lobes subacute, widely diverging, notched subapically, tips unequal in size (inner longer than outer), single seta placed in the notch, single dorsolateral seta on the surface.

Sexual dimorphism: No sexual or size-dependent variation observed as the individual is unique.

Molecular identification: Following the definition given by Pleijel et al. (2008), the sequence of the holotype juvenile of O. claudei (SMF-56781, GenBank accession number MW 377945 View Materials ) is designed as a hologenophore of all obtained sequences. The species has received also a Barcode Index Number from BOLD: AEA4699 (dx.doi. org/10.5883/ BOLD: AEA 4699 ) .

Distribution: Sea of Okhotsk ( Fig. 25 View Figure 25 ), 3307 m.

MOLECULAR INVESTIGATION

Each of the morphologically recognized species received a unique Barcode Index Number. Across all species, the intraspecific diversity calculated on haplotypes is low, ranging from 0.002 ( O. lesci ) to 0.005 ( O. henrici ) for both K2P and p -distance. Each of the species is represented by three haplotypes ( Table 2 View Table 2 ; Fig. 24B View Figure 24 ). An exception is O. claudei , as only one individual of this taxon was collected. The distances between the studied taxa varies from 0.059 to 0.238 of p -distance and from 0.061 to 0.289 of K2P ( Table 3). The lowest interspecies distances are noted between O. lesci and O. ingolfi , irrespective of the measures applied. The highest values are observed for O. henrici and O. claudei for both measures and for O. henrici and O. ingolfi for p -distance only ( Fig. 24A View Figure 24 ).

The haplotype networks show a star-like topology ( Fig. 24B View Figure 24 ). In O. lesci , the central, ancestral and dominant haplotype is present at five stations including the stations situated on both sides of the KKT. In O. henrici and O. teresae , the central, ancestral haplotypes are missing.