Metatanais bipunctatus, Blazewicz-Paszkowycz & Zemko, 2009

Blazewicz-Paszkowycz, Magdalena & Zemko, Karol, 2009, A new species of Metatanais Shiino, 1952 (Crustacea, Tanaidacea, Paratanaoidea) from Australian coral reefs, with a redefinition of the genus, ZooKeys 18 (18), pp. 129-141 : 133-139

publication ID	https://doi.org/ 10.3897/zookeys.18.114
publication LSID	lsid:zoobank.org:pub:7760E22B-E679-4821-9993-E90BE9CD1FB2
DOI	https://doi.org/10.5281/zenodo.3791519
persistent identifier	https://treatment.plazi.org/id/910A8795-A472-DE62-86DE-FE8083EB337E
treatment provided by	Plazi
scientific name	Metatanais bipunctatus
status	sp. nov.

Treatment

Metatanais bipunctatus View in CoL sp. n.

urn:lsid:zoobank.org:act:0DFA750C-CDC5-43FB-9083-CB8FD71AA9CA

Figs 3–5 View Figure 3 View Figure 4 View Figure 5

Material examined: Holotype: Female (1.7 mm) ( MTQ W31164), CGLI 31 , 14.68039°S, 145.4453°E, Lizard Island , Casuarina Beach, dead coral, depth 1 m, 15 GoogleMaps

Apr 2008. Paratypes: 1 specimen (1.5 mm), ( MTQ W31164), CGLI 20, 14°64.553’S, 145°65.335’E, North Point, dead coral rubble, depth 0.5–1.5 m, 12 Apr 2008. 1 specimen, dissected in slides ( WAM C42469), NIN 17, Western Australia, Ningaloo Reef, off Tantabiddy, reef front 21.92833°S, 113.9196°E, dead Acropora head, depth 13–15 m, 17 Jun 2008.

Diagnosis: Body over four times as long as wide. Antennule article 1 less than twice as long as wide. Pereopod 4–6 propodus compact (about three times as long as wide), with spiniform setae ventrally.

Etymology: bipunctatus [Latin]: with two spots, referring to presence of dorsal orange spots, one on the posterior of the carapace and one on pereonite 6.

Description: Female without oostegites ( Fig. 1A, B View Figure 1 ) 1.5 mm long. Body about 4.5 times as long as wide. Carapace 16% of body length, as long as wide, without rostrum, tapering towards the anterior, with mid-dorsal orange spot near posterior margin. Pereon about half of total body length. All pereonites wider than long, margins rounded in dorsal view. Pereonite 1 0.25 times as long as wide; pereonites 2 and 3 subequal and little longer than pereonite 1. Pereonites 4 and 5 subequal, 0.4 times as long as wide. Pereonite 6 subequal to pereonite 2, with orange spot mid-dorsally. Pleonites subequal in size (0.15 times as long as wide); pleotelson as long as combined length of pleonites 3 to 5, tapering posteriorly, produced medially.

Antennule ( Fig. 2A View Figure 2 ) three-articled; article 1 barrel-shaped, half as long as carapace, less than twice as long as wide, with two simple, blunt setae on distal upper margin, distally overlapping base of article 2. Article 2 as long as wide, about one fifth as long as article 1, with one seta. Article 3 subequal in length to article 2, but slightly narrower, with one long and two short rod setae and one aesthetasc distally.

Antenna ( Fig. 2B View Figure 2 ) six-articled. Article 2 1.1 times as long as wide, with one setae distally. Article 3 little shorter than wide, half as long as article 2, with one simple setae distally. Article 4 compact, about twice as long as wide, and subequal in length to article 2, with two pinnate setae along the dorsal margin. Article 5 1.3 times as long as wide, with one simple seta distally. Article 6 minute, with two long and two short distal setae.

Mouthparts: Labrum ( Fig. 2C View Figure 2 ) hood shaped, with fine setae. Left mandible ( Fig. 2D View Figure 2 ) molar robust, as long as wide, incisor with sharp processes distally; lacinia mobilis of moderate size, distal margin crenulated; right mandible ( Fig. 2E View Figure 2 ) incisor process simple, lacinia mobilis absent. Maxillule ( Fig. 2G View Figure 2 ) endite with eight spiniform setae distally and setose outer margin. Palp ( Fig. 2 View Figure 2 G') with two articles, distal article tipped by two long simple setae. Maxilla ( Fig. 2H View Figure 2 ) triangular, naked. Maxilliped ( Fig. 2F View Figure 2 ) bases semi-fused; endites plate-like, exceeding bases of maxilliped distally and laterally, with one long simple setae distally and anterolateral rows of fine setae. Maxilliped palp article 1 with simple seta on outer margin; article 2 wedge-shaped with two plumose and one simple seta on the inner margin; article 3 with one plumose seta and three simple setae on the inner margin; article 4 with five plumose setae distally and one simple seta on outer margin.

Epignath ( Fig. 2I View Figure 2 , I') narrow with six short simple setae on distal margin.

Cheliped ( Fig. 3A View Figure 3 ) basis as long as wide; similar in size to sidepiece. Merus wedgeshape, naked. Carpus 1.3 times as long as wide, with one seta on dorsal margin. Propodus massive about twice as long as wide; palm little longer than dactylus; fixed finger

with strongly calcified inner margin; two small setae on ventral margin. Dactylus little longer than well-calcified unguis.

Pereopod 1 ( Fig. 3B View Figure 3 ) coxa with one simple seta on dorsal margin; basis about as long as combined length of carpus and propodus, 5.3 times as long as wide. Ischium naked. Merus as long as carpus, naked. Carpus with two spines and one seta distally ( Fig. 3 View Figure 3 B'). Propodus ( Fig. 3 View Figure 3 '') 1.4 times as long as carpus, with two dorso-distal rod setae and one minute spine ventrally. Dactylus shorter than unguis.

Pereopod 2 ( Fig. 3 View Figure 3 C–C'') similar to pereopod 1, but propodus ( Fig. 3 View Figure 3 C'') with one rod seta dorso-distally.

Pereopod 3 ( Fig. 3D View Figure 3 ) similar to pereopod 2, but merus with two minute distal spines ventrally, propodus without simple setae on the dorsal margin.

Pereopod 4 ( Fig. 3E View Figure 3 ) basis broken; ischium with one simple seta, merus with two short spines disto-ventrally; carpus with one rod seta and spine distally, propodus with one simple seta distally, one spine ventrally and one fine seta in middle of dorsal margin; dactylus twice as long as unguis, curved.

Pereopod 5 ( Fig. 3F View Figure 3 ) similar to pereopod 4, but ischium naked and carpus with three thick short distal spines.

Pereopod 6 ( Fig. 3G View Figure 3 ) similar to pereopod 5, but propodus with four short simple setae distally.

Uropod ( Fig. 3H View Figure 3 ) rudimentary; uniramous, basal article wider than long, embracing base of ramus article 1; article 2 rudimentary with one short and four long rod setae distally.

Distribution. Th e species was recorded from reefs around Lizard Island (northeastern Australia) and Ningaloo Reef, (north-western Australia) in coral rubble and on dead heads of coral at depths down to 15 m.