Noodtorthopsyllus tageae sp. nov.

(Figs 1–13)

Type locality. Brazil, São Paulo State, São Sebastião, São Francisco Beach (23º45’42.6” S, 45º24’27.7” W).

Type material. Holotype Ƥ in ethanol (reg. no MZUSP 19623), collected September 1990. Undissected paratypes (in ethanol) deposited in MZUSP (reg. nos 19624–19625) are 2 ƤƤ and 2 33 (collected September 1990) and 2 ƤƤ and 2 33 (collected March 1991). Additional undissected paratypes (in ethanol) deposited in NHM are 2 ƤƤ [reg. nos 2009.8 (collected September 1990) and 2009.10 (collected March 1991)] and 2 33 [reg. nos 2009.9 (collected September 1990) and 2009.11 (collected March 1991)]. Dissected paratypes are retained in the collection of C.E.F. da Rocha (Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo): 1 Ƥ and 1 3 (September 1990); 1 Ƥ and 1 3 (collected March 1991). Registered naupliar and copepodid specimens used in the study of caudal ramus development deposited in NHM. All material collected from the type locality by G. Lotufo.

Description. FEMALE (Figs 1–6, 10–12). Total body length 494–575 μm (N = 8; mean = 540 μm; holotype = 535 μm). Largest width measured at posterior margin of cephalic shield: 108–124 μm (N = 8; mean = 117µm). Body (Fig. 1 A–B) cylindrical, without marked constrictions between somites. Urosome slightly narrower than prosome.

Rostrum (Fig. 2 A) triangular, with broad base; completely defined at base; with pair of tiny sensillae subterminally and a midventral tube-pore near apex; dorsal surface with pattern of integumental depressions.

Cephalothorax (Fig. 1 A–B) tapering towards rostrum; pleural areas moderately developed; integument with small, round depressions forming essentially symmetrical pattern; ornamentation consisting of sensillae and minute spinules as illustrated; posterior margin serrate. Pedigerous somites (Fig. 1 A–B) covered with minute spinules and ornamentation consisting of sensillae and pores as illustrated; posterior margins serrate. Urosome (Figs 1 A–B; 2B; 10A, C–E) 5-segmented, comprising P5-bearing somite, genital double-somite, 2 free abdominal somites and anal somite. Urosomites with surface ornamentation consisting of sensillae and minute spinules; ventral and ventrolateral spinules arranged in symmetrical pattern (Figs 2 B; 10A, E); posterior margin serrate (Fig. 10 C). Genital double-somite (Figs 1 A–B; 2B; 10A, E) completely fused ventrally; original segmentation indicated by transverse, serrate surface ridge dorsally and dorsolaterally; surface ornamentation around genital field consisting of minute spinules and pores (Fig. 2 C); large copulatory pore located in median depression (Figs 2 C; 10A–B); gonopores fused medially forming single genital slit covered on both sides by opercula derived from sixth legs; P6 with small protuberance bearing 1 pinnate seta (Fig. 2 A). Anal somite (Figs 1 A–B; 2D) with moderately developed, rounded, serrate anal operculum flanked by row of multiserrate processes; anal opening (Fig. 2 D) with fringe of fine setules; surface ornamentation consisting of a pair of sensillae and pores dorsally, and 2 pairs of pores ventrally; midventral posterior margin with serrate projections (Fig. 10 D).

Caudal rami (Figs 2 B, D; 3A–B; 11A) short, slightly longer than maximum width; tapering posteriorly. Each ramus with 1 ventral pore and 7 setae of which most are flanked by spinous processes: seta I naked, shortest and closely set to naked seta II; seta III naked and positioned ventrolaterally; setae IV and V fused basally; seta V consisting of styliform proximal part, sparsely covered with minute denticles, and very short bi-setular distal part (Figs 2 D; 11B); seta VI naked; seta VII tri-articulate at base. Surface ornamentation of ramus consisting of minute spinules as shown in figures 2D, 3A–B and 11A.

Antennule (Fig. 3 C) 4-segmented and with complex reticulate surface pattern as shown in figure 11D. Segment I with long posterior and short anterior spinous process, one setular array and one spinular patch; posterior margin of segment II without real process but with rudimentary, blunt protuberance; segment II with 2 modified setae bearing circular array of spinules (Fig. 11 D); segment III longest with aesthetasc fused basally to seta and set on distinct pedestal; segment IV without aethetasc. Armature formula: I-[1], II-[6+ 1 plumose + 2 modified], III-[8+ 1 pinnate + (1+ae)], IV-[8+ 1 pinnate + acrothek]. Acrothek reduced, consisting of 2 basally fused setae.

Antenna (Figs 3 D; 11E–F) 3-segmented comprising coxa, allobasis and free 1-segmented endopod. Coxa small with no ornamentation. Basis and proximal endopod segment fused forming elongate allobasis, with minute spinules along abexopodal margin, abexopodal seta and exopod absent. Free endopod slightly shorter than allobasis; ornamented with row of spinules distally; medial armature consisting of 1 pinnate spine, 2 setae (1 small naked and 1 pinnate) and 1 short spinule (Fig. 11 F); apical armature consisting of 2 pinnate spines and 3 geniculate setae, outermost one of which fused basally to short seta.

Labrum (Fig. 4 A) well developed, with spinular ornamentation along distal margin; no pores discernible. Mandible (Fig. 4 B–C). Coxa with well developed gnathobase bearing several multicuspidate teeth and 1 pinnate seta around distal margin (Fig. 4 C). Palp small and uniramous; basis asetose; exopod absent; endopod with 1 plumose seta medially, 1 subapical naked seta and 2 apical naked setae fused at base (Fig. 12 B).

Maxillule (Figs 4 D; 12A). Praecoxa with a row of spinules along distal outer margin; arthrite well developed, with 7 spines/setae and a small spinule around distal margin (Fig. 12 C), 1 pinnate seta and a row of spinules along inner margin and 2 naked setae on anterior surface. Coxa with cylindrical endite bearing 1 geniculate spine and 1 naked seta distally, and a row of setules along outer margin. Basis with 2 endites and spinular row around outer margin; proximal endite with 2 naked setae; distal endite with 1 geniculate spine and 2 pinnate setae. Endopod incorporated into basis, represented by 3 naked setae. Exopod 1-segmented, with 2 pinnate setae (Fig. 12 B).

Maxilla (Figs 4 E; 12A). Syncoxa with bilobate outer margin, each lobe bearing spinules or setules as figured; medial margin with 3 endites; praecoxal endite vestigial, represented by a single 1 seta; proximal coxal endite with 2 naked setae and 1 spine which is fused to the endite, spoon-shaped and irregularly serrate at the apex (serrations only discernible in SEM micrographs; Fig. 12 D); distal coxal endite with 1 pinnate and 2 naked setae. Allobasis drawn out into strong, pinnate claw (Fig. 12 D); accompanying armature consisting of 3 naked setae. Endopod incorporated into basis and represented by 2 naked setae.

Maxilliped (Figs 5 A; 12A) with 1 pinnate seta and 2 rows of spinules on syncoxa. Basis with row of spinules along distal area of palmar (= inner) and outer margins. Endopod drawn out into long, distally pinnate claw; accompanying armature consisting of 1 long and 1 vestigial naked setae.

P1 (Fig. 5 B) with well developed praecoxa, with patch of minute spinules on anterior surface and serrate crest at outer margin. Coxa with patches of minute spinules and a row of stronger spinules on anterior surface; outer margin with 2 serrate crests, each ornamented with anterior row of minute spinules. Basis with short spine on anterior surface and naked seta at outer distal corner; ornamentation consisting of rows of minute spinules along inner and distal margins. Exopod 3-segmented; exp-1 with spinules along outer and distal margins, and 1 pinnate spine near outer distal corner; exp-2 with row of spinules along outer margin and 1 geniculate seta at outer distal corner; exp-3 with 4 geniculate setae of different lengths. Endopod 2-segmented, 1.4 times as long as exopod; enp-1 at least twice longer than enp-2, with spinules along inner and outer margins, and 1 small inner seta. Enp-2 with row of spinules along outer margin, 2 rows of stout spinules on anterior surface and 1 denticulate claw and 1 long geniculate seta apically.

P2–P4 (Figs 5 C; 6A–C). Praecoxa without crest but with spinular pattern on anterior surface as figured. Coxae of P2–P3 with rows of minutes spinules on anterior surface and with outer serrate crest accompanied by smaller crest proximally; P4 without coxal crests. Basis with row of tiny spinules along distal margin; with naked outer seta. Exopod 3-segmented with spinular rows as figured. Endopods 1- (P3–P4) or 2-segmented (P2); P4 endopod smaller than P3 endopod; segment(s) with rows of spinules along inner and outer margins as figured. Spine and setal formula as follows:

P5 (Figs 6 D; 11C) not fused to supporting somite; baseoendopod and exopod fused forming triangular plate; anterior surface with 3 secretory pores and dense irregular pattern of minute spinules; armature consisting of 4 pinnate spines (3 small and 1 very long), 1 smooth spine, 1 weakly serrate spine, and 2 naked setae (one of which being the outer basal one); 2 innermost elements of endopodal origin; margin between outer basal seta and outer spine produced into serrate outgrowth.

MALE (Figs 7–9, 13). Body length 436–535 μm (N = 8; mean = 491 μm). Largest width measured at posterior margin of cephalic shield: 105–128 μm (N = 8; mean = 116 μm). Prosome (Fig. 7 A) 4-segmented, comprising cephalothorax and 3 free pedigerous somites. Urosome (Fig. 7 A–B) 6-segmented, comprising P5- bearing somite, genital somite, 3 abdominal somites and anal somite. Ornamentation of cephalothorax and body somites comparable to that of the female. Caudal rami (Fig. 8 A–B) similar to the female.

Antennule (Figs 8 C–E; 13B–D) 5-segmented, chirocer with geniculation between segments IV and V. Segment I with long posterior and short anterior spinous process; dorsal surface with few long setules; posterior margin of segment II without real process but with rudimentary, blunt protuberance; segment II with 2 modified setae bearing circular array of spinules; segment IV swollen, with pattern of minute denticles (Figs 8 D; 13B), modified elements along anterior margin (Fig. 13 D) and aesthetasc fused basally to seta and set on distinct pedestal; segment V produced into anteriorly directed, recurved spinous apex (Figs 8 C; 13B–C), without aesthetasc. Armature formula: I-[1], II-[7 + 2 pinnate + 2 modified], III-[10 + 1 pinnate], IV-[8 + 1 pinnate + 3 modified elements + (1 + ae)], V-[8 + 3 pinnate + 1 spine]. Acrothek reduced, consisting of 2 basally fused setae.

P1 endopod (Fig. 9 A) 2-segmented; enp-1 with inner seta well developed and pinnate (marked with asterisk in Fig. 9 A); enp-2 proportionately longer than in Ƥ; with row of spinules along outer margin and 2 rows of stout spinules on anterior surface (Fig. 13 A).

P3 endopod (Fig. 9 B) with constriction subdividing segment in two pseudosegments; swollen proximal pseudosegment with long sigmoid apophysis, arising from the inner margin and 1.7 times as long as entire endopod; distal pseudosegment 3.3 times length of proximal one, bearing 1 long pinnate seta apically, 1 minute spinous outer process (representing vestigial seta) and few small spinules near outer distal corner.

P4 endopod (Fig. 9 C) 1-segmented and slightly more slender than in Ƥ.

P5 (Fig. 9 D) not fused to supporting somite; baseoendopod and exopod fused, forming triangular plate; anterior surface covered with minute spinules; armature consisting of 4 distinctly pinnate setae/spines, 2 minutely pinnate spines and 2 naked setae (outer one of which representing outer basal seta); 2 innermost elements endopodal in origin.

Sixth pair of legs (Figs 7 B; 9E) asymmetrical; represented on both sides by a small plate, one side fused to ventral wall of genital somite, other side articulating at base with genital somite and covering single functional gonopore; ornamentation consisting of minute spinules on anterior surface and row of spinules along distal margin; outer distal corner with naked outer and pinnate inner seta. Spermatophore very large (about 1/4 of body length) and slender, with long, curved neck (Figs 7 A; 10E–F).

Variability. P4 enp-1 presumably bears 2 inner and 2 distal setae in the normal condition (formula [220]; 7 ƤƤ and 8 33 examined), however, in 10 females only one inner seta was present (formula [120]), and in 4 females P4 enp-1 displayed [220] on one side and [120] on the other side. A similar left/right asymmetry was observed in the holotype of Cristacoxa petkovskii Huys, 1990 (cf. Huys 1990: Figs 4 B–C). No setal variability was observed in the males examined.

Etymology. The new species is named in honour of Prof. Tagea Kristina Simon Björnberg (Centro de Biologia Marinha – Universidade de São Paulo) in recognition of her significant contributions to the taxonomy of Copepoda.