Phoxokalliapseudes singaporensis, Drumm & Heard, 2011

DRUMM, DAVID T. & HEARD, RICHARD W., 2011, Systematic revision of the family Kalliapseudidae (Crustacea: Tanaidacea), Zootaxa 3142 (1), pp. 1-172 : 50-58

Phoxokalliapseudes singaporensis n.sp.

( Figs 30–34 )

paratypes: 6 adult males (1 dissected), 1 adult female (dissected), 21 juveniles, 4 mancas ( ZMUC CRU –20387), Indo–Pacific, Singapore, shallow water, consul. Sv. Gad, 1905–07 .

Diagnosis (adult male). Rostrum rounded. Pleotelson gently tapering posteriorly to indented tip and with two terminal plumose setae. Antennule first peduncle article with one short ventral spiniform seta (female with one long and one short ventral spiniform setae); accessory flagellum of 4 or 5 articles; proximal articles of main flagellum with small cluster (<5) of aesthetascs. Antenna first peduncle article with one simple seta on outer subdistal corner; third peduncle article with one plumose seta on inner margin; flagellum with six articles, the second and third articles with several pectinate setae on outer margin. Labrum complex with four strong cusps. Terminal spiniform seta of mandibular palp approximately four times as long as broad. Cheliped propodus with large spine on inner surface near dactylus insertion, approximately 3.5 times as long as broad. Cheliped and pereopod 1 exopodite with two plumose setae. Pereopod 5 propodus with short bipinnate setae on inner and outer surfaces. Pereopod 6 dactylus longer than ischium, merus, carpus and propodus combined, with one subterminal seta. Uropod basal article approximately 2.7 times as long as broad; exopodite with three articles, last article approximately 2.5 times as long as second article.

Description. Adult male. Body ( Fig. 30A ): length approximately 5.3 mm, 5.5 times as long as broad.

Carapace ( Fig. 30A ). As long as broad, one pair mid–lateral and dorsal setae; rostrum rounded.

Pereonites ( Fig. 30A ). Pereonites 4 and 5 longer than others and pereonite 6 shortest; pereon narrowing posteriorly; one pair anterolateral setae; hyposphaenia present on all pereonites.

Pleon ( Fig. 30A ). Pleonites subequal; epimera rounded, with several plumose setae, two pairs dorsolateral simple setae; hyposphaenia present on all pleonites. Pleotelson shorter than last three pleonites combined, gently narrowing posteriorly to an indented tip, with two terminal plumose setae.

Antennule ( Figs. 30B, C ). First peduncle article approximately 2.3 times as long as second and third articles combined and approximately 2.5 times as long as maximum width, with some simple setae on inner margin and several simple and broom setae on outer margin; ventral surface with one small subdistal spiniform seta. Second peduncle article approximately three times shorter than first article, with several simple and broom setae. Third article slightly longer than fourth article (including common article). Outer flagellum same length as first peduncle article, with 12 articles, small cluster of aesthetascs on proximal articles and decreasing in number distally. Inner flagellum with 5 articles, last article with four terminal setae (three simple and one broom).

Antenna ( Fig. 30D ). First peduncle article with one simple seta on outer subdistal corner and medial extension bearing six plumose setae. Second peduncle article naked and squama with three simple setae. Third peduncle article with one plumose seta on inner margin. Peduncle article 4 (last) approximately same length as flagellum, with double row plumose setae, one proximal broom seta. Flagellum with 6 articles, second and third articles with several pectinate setae and one or two plumose setae on each article, distal article with four terminal simple setae.

Labrum ( Fig. 30E ) straight–edged posteriorly, finely setose and with four strong anterior cusps.

Mandibles ( Figs. 30F, G ). Left mandible ( Fig. 30G ): incisor process with approximately 11 and lacinia mobilis with approximately six teeth; spine row with five spiniform setae. Right mandible: incisor process with two large and four small teeth; spine row with five spiniform setae. Palp ( Fig. 30F ) with a short terminal spiniform seta, approximately four times as long as broad.

Labium ( Fig. 30H ) with short hair–like setae on anterior margin and spinulate on outer margin. Palp with long hair–like setae on margins; ending in short acuminate inner tip.

Maxillule ( Fig. 30I ). Inner endite bearing four terminally setulate setae and dense rows of hair–like setae on outer margin. Outer endite with eleven long and one short spiniform setae, two subterminal setae and dense rows of hair–like setae on outer margin.

Maxilla ( Figs. 31A, B ). Inner lobe of fixed endite with posterior row of five serrate spiniform setae and with long anterior row of filter setae. Outer lobe of fixed endite with four distal serrate setae, several simple and pectinate setae, and one spiniform seta on posterior face. Inner lobe of moveable endite with several simple tricusped setae. Outer lobe of moveable endite with two pectinate and two plumodenticulate (bearing proximal setules and distal denticles). Inner margin spinulate.

Maxilliped ( Fig. 31C ). Basal article fringed with plumose setae on outer margin, inner margin naked. First article of palp with four inner simple setae and one outer simple seta. Last three articles of palp with double row of

Cheliped ( Figs. 31E, F ). Basis with several simple setae on ventral margin. Merus as long as broad, with two distal simple setae and one short simple seta midway on ventral margin. Carpus approximately 2.2 times as long as broad, with double row of long, plumose setae ventrally and one simple seta on dorsodistal corner. Propodus with diagonal row of long, plumose setae on inner face; fixed finger with several simple setae just proximal to distal unguis; cutting edge with short tooth proximal to several small round protuberances interspersed with short seta;

palm with large, distinctive spine near dactylus insertion. Dactylus with three simple setae on inner surface; cutting edge with several setae (<10). Exopodite with two plumose setae.

C, D = 0.1 mm; E, G = 0.2 mm.

Pereopod 1 ( Figs. 31G, H ). Basis approximately 2.7 times as long as broad, with several short simple setae on dorsal margin, one spiniform and simple setae on ventrodistal corner. Ischium with two simple setae. Merus shorter than and as broad as basis, with several simple setae distally and on ventral margin, and one spiniform seta on each distal corner. Carpus approximately 2.3 times shorter than merus, with several simple setae and two ventrodistal and one dorsodistal serrate spiniform setae. Propodus shorter than carpus, with several simple setae and five ventral and two dorsal serrate spiniform setae, one broom seta on dorsal margin, and one pectinate seta distally on the inner surface. Dactylus represented by sensory organ, shorter than propodus, with several long, terminal sensory setae with two setae on inner surface; unguis absent. Exopodite with two plumose distal setae.

Pereopod 2 ( Fig. 32A ). Basis approximately 2.6 times as long as broad, with two broom setae on dorsal margin, two ventral subdistal simple setae (one long and one short). Ischium with one simple seta on ventrodistal corner. Merus approximately same length as carpus, with three simple and one spiniform setae on ventral margin. Carpus approximately 1.8 times as long as broad, with several simple setae distally and on ventral margin, and four spiniform setae. Propodus approximately three times shorter than basis, with several distal simple setae, one middorsal broom seta, four ventral and one dorsodistal spiniform setae, and three spiniform setae on outer surface. Dactylus shorter than basis, slightly longer than carpus and propodus combined; digitiform lobe present near base, with four aesthetascs; unguis fused with dactylus.

Pereopod 3 ( Figs. 32B, C ). Similar to pereopod 2. Carpus with eight spiniform setae. Propodus with five ventral serrate spiniform setae.

Pereopod 4 ( Fig.32D ). Basis approximately 1.7 times as long as broad, with one short ventrodistal seta, two proximal broom setae and one simple seta on dorsal margin. Ischium with two ventrodistal simple setae (one long and one short). Merus shorter than carpus, with three simple and three spiniform setae. Carpus with nine spiniform setae and two dorsodistal simple setae. Propodus with nine serrate spiniform setae on outer surface, nine serrate spiniform setae on inner surface, several short bipinnate setae on outer and inner surfaces, and one proximal broom seta on dorsal margin. Dactylus shorter than propodus, with a tuft of approximately seven aesthetascs; unguis absent.

Pereopod 5 ( Figs. 32E, F ). Similar to pereopod 4. Carpus with 13 spiniform setae. Propodus with one short dorsal margin, and five plumose setae on ventral margin. Ischium with one simple seta on ventral margin. Merus longer than ischium, with three plumose setae on dorsal margin and one simple seta on ventral margin. Carpus approximately three times as long as merus, with six simple setae on ventral margin, four plumose setae on dorsal margin, and one simple seta subdistally on outer surface. Propodus shorter than the carpus, with two long spiniform setae on ventral margin and 21 short bipinnate setae.

Dactylus longer than ischium, merus, carpus and propodus combined, with one subdistal seta; unguis absent.

Pleopods ( Fig. 3A). Basal article with four long plumose setae. Exopodite with 19 plumose setae and endopodite with 21 plumose setae.

Uropods (Fig. 33B). Basal article approximately 2.7 times as long as broad, with several short, subdistal simple setae. Exopodite with three articles, distal article longest, approximately 2.5 times as long as second article, with four simple setae. Endopodite (exact number of articles difficult to determine due to incomplete fusion in some of the articles) as long as last three pereonites and pleon combined.

Adult Female. Very similar to male but with the following differences:

Antennule (Fig. 33D). First peduncle article with two ventral spiniform setae (one long and one short). Accessory flagellum with four articles. Main flagellum with nine articles, one aesthetasc on articles 4, 5 and 7.

Antenna (Fig. 33E). Squama with four simple setae.

Cheliped (Figs. 33F, G). Less robust. Propodus lacking large spine near dactylus insertion; cutting edge with short spinules interspersed with a tubercle. Dactylus cutting edge with several spinules (> 10) increasing in length distally.

Pereopod 6 ( Fig. 34A ). Merus with two plumose setae on dorsal margin. Carpus with five plumose setae on dorsal margin. Propodus with four long spiniform setae and approximately 19 short bipinnate setae. Dactylus shorter than carpus and propodus combined.

Type locality. Singapore, Indo–Pacific (Fig. 1, number 11).

Geographic distribution. Known only from type locality.

Remarks. Phoxokalliapseudes singaporensis n. sp. is similar to P. multiarticulus ( Guţu, 2006) but can be distinguished from this species by 1) having fewer ventral spiniform setae on the first peduncle antennule article, 2) fewer articles in the inner (accessory) flagellum of the antennule (4 or 5 in singaporensis and 6 or 7 in multiarticulus ), 3) fewer aesthetascs in the male antennule, 4) only one plumose seta on the third article of the antenna peduncle (3 in multiarticulus ), 5) a larger spine on the inner surface of the male cheliped propodus near dactylus insertion and lack of a hook–shaped spine proximally on dactylus, 6) fewer sensory setae on the dactylus of pereopods 2, 3, 4, and 5, 7) the absence of a spiniform seta on the inner distal corner of the uropod basal article, and 8) a much smaller body size.

The chela of the subadult male (3.5 mm TL, Fig. 34B ) differs from the adult male chela by having a larger tooth on the cutting edge of the fixed finger and by lacking the large spine on the inner surface of the propodus near the dactylus insertion.

Genus Cristapseudes B ă cescu, 1980

Cristapseudes Băcescu, 1980: 360 . Guţu, 1996a: 73, 75, 1996b: 137, 141. Bamber, 1998: 184. Guţu, 2001: 69, 70. Bamber et al., 2003: 52.

Type species. Kalliapseudes omercooperi Larwood, 1954 .

Diagnosis. Modified according to Guţu (2006).

Antennule accessory flagellum with 3–4 articles. First peduncle article of antennule showing strong sexual dimorphism (much more robust in female). Antenna peduncle with double row of plumose setae on last (fourth) article. Labrum with cusps. Cheliped and pereopod 1 with or without exopodite. Female and male chelipeds with propodus only slightly longer than carpus. Pereopods 2 and 3 lacking proximal sensory lobe on dactylus. Basis of pereopods 4 and 5 globose. Dactylus of pereopods 4 and 5 thick, with sensory setae; unguis absent. Pereopod 6 with normal dactylus; unguis present. Oostegites on pereopods 1–4. Sexual dimorphism of cheliped and antennule,

with male antennule having more aesthetascs and first peduncle article longer and narrower.

Species. Cristapseudes omercooperi ( Larwood, 1954) , C. siamensis Guţu and Angsupanich, 2005 , C. unicus Guţu, 2006 , C. exocladum n. sp.

Remarks. Bacescu (1980) erected the genus Cristapseudes to include Kalliapseudes omercooperi Larwood, 1954 , which is characterized by the absence of exopodites on the cheliped and first pereopod and by the absence of a setose, proximal digitiform lobe on the dactylus of pereopods 2 and 3. The phylogenetic analysis showed that these characteristics are homoplasies and thus should not be used to define genera. The genus is diagnosed by having a sexually dimorphic 1 st antennule peduncle article (much more robust in the female) and pereopods 4 and 5 having a globose basis. Labral cusps are present in C. exocladum n. sp. and C. omercooperi , but unfortunately are unknown in C. unicus and C. siamensis .

Figures

FIGURE 30. Phoxokalliapseudes singaporensis n. sp., adult male. A, dorsal view of body; B, antennule (dorsal); C, 1st peduncle article of antennule (ventral); D, antenna; E, labrum complex; F, right mandible; G, left mandible incisor process and lacinia mobilis; H, labium; I, maxillule. Scale bars: A = 0.4 mm; B, D = 0.2 mm; E, F = 0.1 mm; H, I = 0.05 mm.

FIGURE 31. Phoxokalliapseudes singaporensis n. sp., adult male. A, maxilla; B, outer lobe of fixed endite; C, maxilliped; D, epignath; E, cheliped (inner); F, exopodite of cheliped; G, pereopod 1 (inner); H, pereopod 1 (outer). Scale bars: A = 0.05 mm;

FIGURE 32. Phoxokalliapseudes singaporensis n. sp., adult male. A, pereopod 2 (outer); B, pereopod 3 (outer); C, pereopod 3 propodus and dactylus (outer); D, pereopod 4 (outer); E, pereopod 5 (inner); F, pereopod 5 propodus and dactylus (inner); G, pereopod 6 (inner). Scale bars: A = 0.2 mm; B–G = 0.1 mm.

FIGURE 34. Phoxokalliapseudes singaporensis n. sp., female with oostegites (A); subadult male (B, 3.5 mm TL). A, pereopod 6 (inner); B, chela (outer). Scale bar = 0.1 mm.