Synapseudes singularis Stępień & Błażewicz, 2018

Heard, Richard W., Stępień, Anna, Drumm, David T., Błażewicz, Magdalena & Anderson, Gary, 2018, Systematic and taxonomic observations on the subfamily Synapseudinae Guţu, 1972 and related metapseudid taxa (Crustacea: Tanaidacea: Apseudomorpha), with the erection of a new genus and descriptions of three new species, Zootaxa 4370 (4), pp. 301-344 : 327-332

publication ID

https://doi.org/ 10.11646/zootaxa.4370.4.1

publication LSID

lsid:zoobank.org:pub:0AC1BCEC-0153-46EF-9C61-592C42214EDF

DOI

https://doi.org/10.5281/zenodo.5979427

persistent identifier

https://treatment.plazi.org/id/03B28783-A526-FF9B-8DEA-FE93FDB4FDF1

treatment provided by

Plazi

scientific name

Synapseudes singularis Stępień & Błażewicz
status

sp. nov.

Synapseudes singularis Stępień & Błażewicz View in CoL , n. sp.

Figures 13–16 View FIGURE 13 View FIGURE 14 View FIGURE15 View FIGURE 16

Diagnosis. Cephalothorax rostrum blunt, distal margin slightly concave. Antennule with peduncle article-1 relatively narrow, about 3.3 times longer than wide, with inner, medial margin armed with single spiniform apophysis or spiniform process. Antenna with six articles, terminating in two long setae. Maxilliped with endite having four coupling hooks. Pereopods 1–3 propodus ventral margin with four spiniform tooth-like setae. Pleonites 1–3 completely delineated. Uropod endopod with four articles. Male unknown.

Material examined. Holotype— female (W53960), CGLI 36 A, 14.38536°S, 145.26599°E, Lizard Island , Granite Bluff, fore reef (mid shelf), coarse coral rubble, depth 15 m, coll. MB. GoogleMaps

Paratypes — One ♀ (W53961), CGLI 25 C, 14.64567°S, 145.45325°E, Lizard Island, North Head, fore reef (mid shelf), depth 12 m, coll GoogleMaps . C. Glasby (CG); five ♀♀ (W53962), CGLI 36 A, parameters as for holotype; two ♀♀ CGLI 0 39, 14.64064°S, 145.45365°E, Lizard Island , Mermaid Cove , North Point, ‘ Washing Machine’, depth 15 m GoogleMaps ; three ♀♀ (W53964), CGLI 039 C; two ♀♀ (W53965), CGLI 040 A, 14.38567°S, 145.29132°E, Lizard Island , MacGillivray’s Reef, smooth rubble, depth 18 m GoogleMaps ; two ♀♀ (W53966), LIZ 09-10 C, 14.61383°S, 145.6182°E, Lizard Island , Yonge Reef, back reef, dead coral heads, depth 12 m, coll GoogleMaps . NLB & MB; two ♀♀ (W53967), LIZ 09- 10E, coral rubble at edge of bommies, depth 7 m; 15 (W53968), LIZ 09-21 A, 14.74669°S, 145.31670°E, Lizard Island , North Direction Island, reef front, dead coral heads, depth 12 m, coll. MB & C. Arango (CA). GoogleMaps

Description of adult female. Body ( Fig. 13A, B View FIGURE 13 ). About 1.25 mm long, 4.7 times longer than wide.

Cephalothorax ( Fig. 13A, B View FIGURE 13 ). About 26% of total body length; rostrum blunt, distal margin slightly concave; eyes with dark pigment and ommatidia.

Pereon ( Fig. 13A, B View FIGURE 13 ). About 62% of body length; pereonites rectangular, pereonites 1, 2 and 4 similar in length, about 0.4 times as long as wide, pereonites 2 and 5 about half as long as wide, pereonite-6 narrowest, about 0.3 times as long as wide; first four pereonites with lateral setae on anterior corner, last two pereonites with additional pair of mid-dorsal setae.

Pleon ( Fig. 13A, B View FIGURE 13 ). About 12% of body length, consisting of three delineated pleonites and pleotelson; all pleonites similar in length.

Pleotelson ( Fig. 13A, B View FIGURE 13 ). About 2.3 times as long as combined length of pleonites, with pair of stout setae on dorsal surface.

Antennule ( Figs 13A, B View FIGURE 13 ; 14A). Peduncle article-1 about 3.3 times as long as wide, with two broom setae, three simple setae and one strong spiniform apophysis on outer margin, and with three inner broom setae, and small distal; apophyses; article-2 about half as long as article-1, with five simple setae, three small spine-like apophyses, and three distal broom; article-3 with two distal setae; article in common with two distal setae. Inner flagellum with three articles, article-1 with aesthetasc, article-2 with distal seta and one aesthetasc; article-3 with three distal setae. Outer flagellum with two articles, article-2 terminating in three long, simple setae.

Antenna ( Figs 13B View FIGURE 13 ; 14B). Peduncle with four articles: article-1 robust, with serrate inner margin and two distal apophyses; article-2 with four apophyses and simple seta; article-3 with three distal apophyses; article-4 longest, about twice that of article-3, with five broom setae along distal margin; flagellum with two articles terminating in two long subequal setae.

Mandible ( Fig. 14C View FIGURE 14 ). Incisor with two blunt lobes, setiferous lobe with reduced, bifurcate lacinia mobilis and three simple setae; molar distally serrate; palp with three-articles, articles 1 and 2 asetose, article-3 with two distal pectinate setae.

Maxillule ( Fig. 14D, E View FIGURE 14 ). Outer endite ( Fig. 14E View FIGURE 14 ) having eight spines and simple setae along outer margin; inner endite ( Fig. 14D View FIGURE 14 ) with four setulate distal setae; palp ( Fig. 14F View FIGURE 14 ) with two long finely pectinate terminal setae.

Maxilliped ( Fig. 14G, H View FIGURE 14 ). Basis as long as wide, naked. Palp article-1 short, compressed, lateral margin expanded and terminating in large robust spine; inner distal margin with long, simple seta extending distally to article-2. Article-2 slightly shorter than wide with four basally swollen, distally pectinate setae and six simple setae (proximal most being longer than article-2). Article-3 slightly longer than wide with five basally swollen, distally pectinate setae, and two short submarginal setae on inner margin. Article-4 about 1.5 times as long as wide, with two basally swollen, distally pectinate setae and three simple setae (subdistal seta distinctly longer than the other two). Endite ( Fig. 14 View FIGURE 14 G’) having inner margin with four coupling hooks and two subdistal setulose setae, and with four distal setulose setae and one setulose spine.

Epignath ( Fig. 14I View FIGURE 14 ). With long distal pectinate seta.

Cheliped ( Fig. 14J View FIGURE 14 ). Basis 1.3 times as long as wide, with three setae along ventral margin. Merus twice as long as wide, with three ventral setae. Carpus 3.3 times as long as wide, with two ventral setae and one subdistal spine. Propodus half as long as carpus, with two setae near insertion of dactylus; fixed finger with three ventral setae and four inner setae.

Pereopod-1 ( Fig. 15A View FIGURE15 ). Basis less than three times as long as wide; ventral margin with three setae, one distal; dorsal margin with single spiniform, subacute, apophysis and three small setae. Ischium narrow, about 0.3 times as long as wide, with one ventral seta. Merus about 1.7 times as long as wide; ventral margin with one seta and one subdistal spiniform seta; dorsal margin with well-developed buttressed distal spiniform seta. Carpus 0.6 times as long as merus; ventral margin with two stout spiniform setae; dorsal margin with large spiniform seta and three distal setae. Propodus subequal to merus; ventral margin with four spiniform setae decreasing in size proximally, one stout setulose seta distally near insertion of dactylus; dorsal margin with broom seta, with one distal stout spiniform and one long, simple seta; inner subdistal face with stout spiniform seta. Dactylus 0.3 times as long as propodus, with one ventral and one dorsal seta; unguis 0.6 times as long as dactylus

Pereopod-2 ( Fig. 15B View FIGURE15 ). Similar, but distinctly smaller than pereopod-1. Basis less than three times as long as wide; ventral margin with two setae, one distal; dorsal margin with single spiniform, apophysis, one simple and two broom setae. Ischium narrow, about 0.3 times as long as wide with one ventral seta. Carpus half as long as merus; ventral margin with two stout spiniform setae; distodorsal and subdistal margins with simple seta and two spiniform plus simple seta, respectively. Propodus about 0.8 times as long as merus, ventral margin with four spiniform setae decreasing in size proximally along ventral margin and short, distal stout setulate seta; dorsal margin with one broom seta, spiniform seta and distal long simple seta; inner subdistal face with stout spiniform seta. Dactylus 0.3 times as long as propodus, with one ventral and one dorsal seta; unguis 0.6 times as long as dactylus.

Pereopod-3 ( Fig. 15C View FIGURE15 ). Similar to pereopod-2, but merus 2.5 times as long as wide, and dactylus half as long as propodus.

Pereopod-4 ( Fig. 15D View FIGURE15 ). Basis 3.5 times as long as wide, with two broom setae on dorsal and ventral margin and one simple setae distoventrally. Ischium with one ventral seta, Merus about 1.2 times as long as wide with one spiniform seta and two simple setae along inner subdistal margin. Carpus subequal to merus, with one simple seta and six spiniform setae. Propodus 1.6 times as long as merus; ventral margin with one proximal and one subdistal spiniform setae, small setulate seta subdistally; dorsal margin with broom seta (not illustrated), four distal setulate, and with small ventral spine, with one spines and plumose seta ventrally and four plumose distodorsal setae. Dactylus half as long as wide, with small ventral and dorsal setae; unguis 0.3 times as long as dactylus.

Pereopod-5 ( Fig. 15E View FIGURE15 ). Basis 3.5 times as long as wide, ventral and dorsal margins with one and two broom setae, respectively. Ischium 0.3 times as long as wide, with one ventral seta. Merus 1.6 times as long as wide with submarginal long distal seta and short subdistal seta. Carpus 0.7 times as long as merus, with three spines and two setae distally and subdistally. Propodus four times longer than wide; ventral margin with one small subproximal and one large subdistal spiniform seta, dorsal margin with broom seta and three distal setulate setae. Dactylus similar to that of pereopod 4.

Pereopod-6 ( Fig. 15F View FIGURE15 ). Basis 3.6 times as long as wide; ventral margin with two small setae; dorsal margin with two broom setae. Ischium 0.3 times as long wide, with one ventral seta. Merus 1.6 times as long as wide, ventral margin with subdistal simple seta, dorsal margin with small distal spiniform seta. Carpus 0.9 times as long merus, with one spine and one distoventral seta, and one distodorsal seta. Propodus twice as long as merus, with small ventral spine, dorsal broom seta, one distoventral spine and three plumose distodorsal setae. Dactylus 0.4 times as long as propodus, with ventral and dorsal seta; unguis 0.6 times as long as dactylus.

Uropod ( Fig. 14K View FIGURE 14 ). Basal article twice as long as wide, with strong apophysis on inner distal margin; exopod biarticulate, distal article terminating in two setae; endopod with four articles, article-3 with two distal broom setae, article-4 terminating in two broom setae and three long simple distal setae.

Male. Unknown.

Etymology. The specific name singularis is derived from Latin meaning ‘one’ or ‘single’, referring to the single spiniform apophysis occurring in the inner mid-margin of antennular article-1.

Remarks. Synapseudes singularis n. sp., S. dispina ; and S. intumescens are distinguished from the other 23 members of the genus by having a combination of the (1) antenna terminating in two long setae, (2) propodus of pereopod-1 with ventral margin having four spiniform setae, (3) first three pleonites completely delineated, and (4) uropod with endopod having four articles. Synapseudes singularis can be separated from S. dispina , S. intumescens and the other members of the genus by having the first peduncular article of the antennule being relatively narrow (about 3.3 times longer than wide) and its inner medial margin armed with a single spiniform apophysis. Also, S. singularis appears unique by having pereopods 1–3 each with a single spiniform apophysis on ventral margin of the basis. For additional characters distinguishing Synapseudes singularis and other members of the genus, refer to Table 3 and Key presented here.

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