Lonchoeidestenhelia prote, Gómez, 2020

Gomez, Samuel, 2020, On some new species of Stenheliinae Brady, 1880 (Copepoda, Harpacticoida, Miraciidae) from north-western Mexico, with the proposal of Lonchoeidestenhelia gen. nov., ZooKeys 987, pp. 41-79 : 41

publication ID	https://dx.doi.org/10.3897/zookeys.987.52906
publication LSID	lsid:zoobank.org:pub:D8C4A3A6-6A30-43E4-BF02-B74E7A670C96
persistent identifier	https://treatment.plazi.org/id/D1A4C714-C914-40D5-B141-4CA9828E2BEE
taxon LSID	lsid:zoobank.org:act:D1A4C714-C914-40D5-B141-4CA9828E2BEE
treatment provided by	ZooKeys by Pensoft
scientific name	Lonchoeidestenhelia prote
status	sp. nov.

Treatment

Lonchoeidestenhelia prote sp. nov. Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11 View Figure 11

Specimens examined.

One female holotype (ICML-EMUCOP-180119-01), one male allotype (ICML-EMUCOP-180119-02), and 14 paratypes (10 females and four males) (ICML-EMUCOP-180119-03) preserved in alcohol, and two female (ICML-EMUCOP-180119-05, ICML-EMUCOP-180119-06) and one male (ICML-EMUCOP-180119-07) paratypes dissected and mounted onto 11, six and seven slides, respectively, all from the type locality; six paratypes (two females and four males) (ICML-EMUCOP-180119-04) from stn 1, preserved in alcohol; one female paratype partially dissected (ICML-EMUCOP-180119-08) (P1-P4 dissected and mounted onto one slide, the rest left intact and preserved in alcohol), and nine paratypes (eight females and one male) (ICML-EMUCOP-180119-09) from stn 10, preserved in alcohol; 18 Jan. 2019. S. Gómez leg.

Additional material examined.

One intersexual individual partially dissected (ICML-EMUCOP-180119-10) (P1-P4 dissected and mounted onto one slide, the rest left intact and preserved in alcohol) from stn 4; 18 Jan. 2019. S. Gómez leg.

Differential diagnosis.

Stenheliinae . Anal operculum present, with minute spinules along posterior margin. P1 EXP2 without inner armature. P2-P4 EXP1 with inner seta. Armature formula of P2 EXP3 and P3 EXP3, 123 and 223, respectively. Female P2ENP3 with outer apical spinous process, with displacement of medial and inner apical setae to subapical inner margin, the latter setae normal, not swollen basally. Female P5 baseoendopod without modified setae. Male P2ENP2 without hyaline flange; outer apical sigmoid, bipinnate, flagellate process with incomplete suture indicating original articulation with the supporting segment, with longitudinal row of modified lanceolate spinules proximally. Outer spine of the male P4ENP3 normal, not sexually dimorphic. Male P5EXP and baseoendopod not fused; exopod with two outermost elements modified into spines. Innermost seta of the male P6 normal.

Description.

Female. Total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 415 µm to 563 µm (mean, 491 µm; n, 12; total body length of holotype, 563 µm); habitus pyriform, widest at posterior end of cephalothorax in dorsal view, tapering posteriad (Fig. 2A View Figure 2 ).

Prosome (Fig. 2A, B View Figure 2 ): Consisting of cephalothorax with fused first pedigerous somite, and second to fourth free pedigerous somites, the latter without expansions nor spinular ornamentation; posterior hyaline frill of cephalothorax and pedigerous somites plain, of fourth pedigerous somite visibly narrower; integument smooth, weakly sclerotized.

Urosome (Figs 2A, B View Figure 2 , 3A-C View Figure 3 ): Consisting of fifth pedigerous somite (first urosomite), genital double-somite (genital (second urosomite) and third urosomites fused), two free urosomites, and anal somite; urosomites without expansions laterally nor dorsally; integument weakly sclerotized.

First urosomite (fifth pedigerous somite): Visibly narrower than preceding somites in dorsal view (Fig. 2A View Figure 2 ), without spinular ornamentation, with dorsolateral sensilla as shown (Fig. 2A, C View Figure 2 ).

Genital double-somite: Slightly wider than long, widest at proximal half; with dorsolateral internal rib marking original division between second (genital) and third urosomite (Figs 2A, C View Figure 2 , 3A, B View Figure 3 ), completely fused dorsally (Figs 2A View Figure 2 , 3A View Figure 3 ) and ventrally (Fig. 3C View Figure 3 ); proximal half (genital somite) without spinular ornamentation, with posterior sensilla as depicted; distal half (third urosomite) with short transverse row of small dorsolateral spinules (Figs 2A View Figure 2 , 3A View Figure 3 ), with sensilla as shown.

Fourth urosomite: With spinular ornamentation (Fig. 3A-C View Figure 3 ) as in distal half of genital double-somite, with sensilla as shown.

Fifth urosomite: With spinular ornamentation (Fig. 3A-C View Figure 3 ) as in distal half of genital double-somite, without sensilla.

Anal somite (Figs 2A-C View Figure 2 , 3A-C View Figure 3 ): Twice as long as broad, maximum breadth measured proximally; maximum length measured at the middle from anterior margin of somite to distal margin of anal operculum, with row of dorsolateral spinules close to joint with caudal rami, with one lateral pore on each side (Figs 2C View Figure 2 , 3A, B View Figure 3 ); anal operculum rounded, with minute spinules along its posterior margin, with one sensillum on each side; ventrally cleft medially, with one pore on each side, with spinular row close to joint with caudal rami (Fig. 3C View Figure 3 ).

Caudal rami (Figs 2A-D View Figure 2 , 3A-C View Figure 3 ): Typically divergent (Fig. 2A, B View Figure 2 ), but sometimes parallel (Fig. 3A, C View Figure 3 ), cylindrical, twice as long as broad, and slightly longer than anal somite; each ramus with one lateral (Fig. 2C, D View Figure 2 ) and one ventral pore (Fig. 3B, C View Figure 3 ); with spinules at base of setae I and II (Figs 2C, D View Figure 2 , 3B View Figure 3 ), and ventrally close to insertion site of seta III (Fig. 3C View Figure 3 ); with seven elements as follows: seta I spine-like, ventral to seta II, the former visibly shorter, both arising subdistally on lateral margin; seta III ventral, subdistal, slightly longer than seta II; seta IV and V situated distally, with fracture plane, rat-tail-like; seta VI issuing at inner distal corner; dorsal seta VII triarticulate at base, situated subdistally close to inner margin.

Rostrum (Figs 2A View Figure 2 , 4A View Figure 4 ): Trapezoidal, not fused to cephalothorax, reaching middle of second antennular segment, bifid, with medial pore and two subdistal sensilla.

Antennule (Fig. 4A View Figure 4 ): Seven-segmented; all segments smooth, except for first segment with spinular row. All setae smooth except for one and two pinnate setae on first and second segments, respectively; second and third segments each with one seta with fracture plane; sixth and seventh segments each with two articulated setae. Armature formula: 1(1); 2(11); 3(8); 4(5+(1+ae)), 5(3); 6(8); 7(4+acro). Acrothek consisting of two setae and one slender aesthetasc fused at their bases.

Antenna (Fig. 4B View Figure 4 ): Allobasis as long as free endopodal segment, inner margin with long spinules on proximal third, with one abexopodal seta arising midway inner margin. Exopod three-segmented, issuing proximally; first and third segments longest, each 3 × as long as wide, second segment shortest, ca. 1.5 × as long as broad; first and second segments with one subdistal pinnate seta each, first segment with spinular row as shown, second segment unornamented; third segment with one lateral proximal pinnate element, and three distal setae, of which two fused basally, with spinular row as depicted. Free endopodal segment elongate, inner margin with spinular row proximally, subdistally with curved row of strong spinules, with medial and subdistal outer fringes; armature consisting of two lateral spines and two accompanying setae, one non-geniculate inner distal element, three distal geniculate spines (of which innermost shortest) and one slender seta, and one outer distal geniculate seta fused basally to slender element.

Mandible (Fig. 5A View Figure 5 ): With relatively short coxa. Gnathobasis wide; with two strong bicuspidate teeth, several smaller bicuspidate teeth, some spinules, and one lanceolate element accompanied by seta. Basis elongate, tapering distally; with transverse spinular rows as shown; with three subdistal setae. Exopod arising from short pedestal, one-segmented, elongate, ca. 4 × as long as wide, tapering distally; with three lateral and three apical slender setae, none of which fused basally. Endopod recurved, twisted over exopod; with three lateral setae, and five distal elements (one short seta and long pinnate element fused basally and to endopod, indicated with an asterisk in Fig. 5A View Figure 5 , one slender pinnate and one strong bare element, and one long element fused to endopod and with hyaline flange in middle part, indicated with an asterisk in Fig. 5A View Figure 5 ).

Maxillule (Fig. 5B View Figure 5 ): Arthrite of praecoxa with two surface setae and seven bare distal elements (one of which a slender seta arising next to ventralmost spine), one spinulose dorsal spine, and one lateral spinulose recurved seta. Coxal endite with three setae. Basis with two endites; proximal endite with four, distal endite with three slender setae. Exopod and endopod fused basally, separated from basis, one-segmented; endopod larger than exopod, with four setae; exopod small, with two setae.

Maxilla (Fig. 6A View Figure 6 ): With large syncoxa with outer spinules as shown; with three endites; proximal endite smallest, with one proximal and two distal setae; middle and distal endites elongate, the latter slightly longer, with three elements each as figured. Basis drawn out into strong claw, additionally with strong spine and two slender setae, one of which arising from elongate setophore. Endopod one-segmented, 2 × as long as wide, with six slender setae.

Maxilliped (Fig. 6B View Figure 6 ): Subchelate. Syncoxa rectangular, ca. 1.5 × as long as wide, outer margin irregular and with medial protrusion; with spinules as shown; with one bare and two spinulose strong elements, of which the bare seta and one spinulose element subdistal and both at the same level, the other arising distally from long pedestal. Basis shorter than syncoxa, oval; with inner and outer spinules as depicted, and two slender distal setae, one of which visibly shorter. Endopod one-segmented, slender, with one claw-like element and one seta.

P1 (Fig. 7A View Figure 7 ): Intercoxal sclerite narrow and elongate, without surface ornamentation. Praecoxa large, triangular, unornamented. Coxa quadrate, with spinular rows as shown. Basis with inner robust and strongly spinulose spine, and outer slender pinnate element; with strong spinules at the bases of inner and outer elements and between rami, and with long slender inner spinules. Exopod three-segmented, reaching tip of first endopodal segment, situated at a lower level than ENP; first segment longest, third segment shortest; all segments without outer nor inner distal processes; with spinular ornamentation as shown; first and second segments without inner seta, third segment with four elements. Endopod three-segmented, situated distally on medial circular outgrowth of basis and at a higher level than EXP; ENP1:EXP length ratio 0.9, ENP1 ca. 1.4 × as long as ENP2 and ENP3 combined; ENP1 and ENP3 without, ENP2 with outer acute distal process; segments with spinular ornamentation as figured; ENP1 with pinnate inner seta arising subdistally; ENP2 with one slender inner seta; ENP3 with three elements (one slender inner seta, one apical pinnate element, and one apical outer spine.

P2 (Fig. 7B View Figure 7 ): Intercoxal sclerite not transversely elongate, trapezoidal, with strong pointed process on distal outer corners, without surface ornamentation. Praecoxa small, triangular, unornamented. Coxa massive, quadrate, with outer spinules proximally and subdistally, with subdistal spinules and one pore close to inner margin. Basis with outer setiform element and strong acute process between rami and on inner distal corner, the latter with slender spinules proximally. Exopod three-segmented, reaching slightly beyond ENP3; EXP1 and EXP2 with inner distal frill, with outer acute distal process, with spinular ornamentation as shown, and with one inner seta; EXP3 with processes as shown, with small outer spinules at base of proximal outer spine, with subdistal pore, with one inner and two apical setae, and three outer spines. Endopod three-segmented; segments with spinules as shown; ENP1 shortest, with subdistal inner pore, with inner and outer acute processes, the former slightly larger, with one slender short inner seta; ENP2 and ENP3 subequal in length, the former with outer acute and small inner process, with two inner setae subequal in length; ENP3 with distal processes as shown, with subdistal inner pore, with one inner seta, two inner apical elements, and one outer distal spine.

P3 (Fig. 8A View Figure 8 ): Intercoxal sclerite not transversely elongate; trapezoidal; wider than in P2; with strong pointed process on distal outer corners; without surface ornamentation. Praecoxa triangular, small. Coxa as in P2 but without inner spinules. Basis as in P2, but with somewhat more slender outer seta. Exopod three-segmented, slightly longer than ENP; segments with spinules as shown; EXP1 and EXP2 with outer acute distal process, without pores, with inner distal frill, and with one inner seta each; EXP3 with outer subdistal pore, with two inner setae, two apical elements, and three outer spines. Endopod three-segmented; spinular ornamentation of segments as depicted; ENP1 shortest, ENP3 longest; ENP1 with small outer and inner distal processes, with inner seta; ENP2 with well-developed outer and small inner distal process, with inner pinnate seta; ENP3 with distal processes as shown, with subdistal outer pore, with two inner and two apical setae, and one outer apical spine.

P4 (Fig. 8B View Figure 8 ): Intercoxal sclerite not transversely elongate; trapezoidal; smaller than in P3; with strong pointed process on distal outer corners; without surface ornamentation. Praecoxa, coxa and basis as in P3 except for comparatively smaller inner distal process of basis. Exopod three-segmented, longer than ENP; spinular ornamentation of segments as shown; EXP1 and EXP2 with outer distal process less developed than in P3, without pores, with inner distal frill, and with inner seta; EXP3 with subdistal outer pore, with three inner setae of which medial visibly stronger, two apical elements, and three outer spines. Endopod three-segmented, reaching tip of EXP2; spinular ornamentation of segments as shown; ENP1 shortest, ENP3 longest; ENP1 with small outer distal process, without pore, with inner pinnate seta; ENP2 with well-developed outer distal process, armature as in previous segment; ENP3 with distal processes as shown, with subdistal inner pore, with two inner setae, two apical elements, and one outer apical spine.

Setal formula of swimming legs as follows:

P5 (Fig. 8C View Figure 8 ): Baseoendopod transversely elongate; with five setae, of which outermost shortest and set close to adjoining element, all setae whip-like without any transformation. Exopod oval, with some outer proximal spinules, with six setae, of which fourth from outer to inner margin shortest.

P6 (Fig. 3B, C View Figure 3 ): Represented by a minute flap covering ventrolateral genital aperture, fused to somite, without surface ornamentation, with one slender seta.

Male. Total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 289 µm to 460 µm (mean, 377 µm; n, 7; total body length of allotype, 415 µm).

Prosome: As in female.

Urosome (Fig. 9A-C View Figure 9 ): Largely as in female except for genital somite and third urosomite separated, and for lateral and ventral spinular ornamentation.

Caudal rami (Fig. 9A-C View Figure 9 ): As in female.

Sexual dimorphism: Expressed in A1, P2ENP, P5, and P6.

Antennule (Fig. 10A, B View Figure 10 ): 10-segmented, haplocer. All segments smooth except for first and seventh segment with spinules as shown. All setae smooth except for one and two pinnate setae on first and second segments, respectively, and one and two modified spine-like elements on seventh and eighth segments. Armature formula: 1(1); 2(11); 3(7+ae); 4(2), 5(5+(1+ae)); 6(1); 7(3); 8(3); 9(4);10(4+acro). Acrothek consisting of two setae and one minute aesthetasc fused at their bases.

Antenna, mandible, maxillule, maxilla, and maxilliped: As in female.

P1: As in female.

P2: EXP (not shown) as in female. ENP (Fig. 10C View Figure 10 ) sexually dimorphic; basis, coxa and ENP1 largely as in female; ENP2 transformed, proximal half globular, distal half triangular, with inner notch indicating former division between ENP2 and ENP3, proximal half with inner long setules, distal half with subdistal pore, proximal half with two inner (one proximal and one medial) small setae, distal half with one inner subdistal strong pinnate element, and one apical sigmoid pinnate process with proximal row of outer spinules modified into lanceolate ornaments.

P3 and P4: As in female.

P5 (Figs 9B, C View Figure 9 , 10D View Figure 10 ): Baseoendopods of both legs fused medially forming a continuous plate; each endopodal lobe with two setae, of which inner well-developed, outer small. Exopod small, discrete; with four elements, of which two outermost spine-like, third element from outer to inner margin shortest, innermost seta longest.

P6 (Fig. 9B, C View Figure 9 , 10E View Figure 10 ): Asymmetrical, only one leg functional; each leg with three setae, of which medial longest, inner and outer elements subequal in length.

Variability. One intersexual specimen (ICML-EMUCOP-180119-10) possesses female antennules, displays genital double-somite (Fig. 11B View Figure 11 ), and lacks dimorphism in swimming legs, but the P5 (Fig. 11A, B View Figure 11 ) seems more of the male type with exopod bearing four elements (but two outer elements long and seta-like), and both baseoendopods fused medially and with two setae (outer small, inner long and pinnate), and the P6 possesses two setae.

Etymology.

The specific epithet from the Greek πρώτη, prṓtē, first, makes reference to the first species of Lonchoeidestenhelia gen. nov. described so far. Gender feminine.

Type locality.

Mexico, Sinaloa State: Urías estuary, stn 2, 23.1587°N, 106.3326°W, depth 1.8 m, organic carbon content 3.99%, organic matter content 6.86%, sand 80.42%, clay 8.29%, silt 11.28%.

Other localities.

Mexico, Sinaloa State: Urías estuary, stn 1: 23.15194°N, 106.3128°W, depth 1.5 m, organic carbon content 3.74%, organic matter content 6.43%, sand 25.31%, clay 35.75%, silt 38.94%, stn 4: 23.1840°N, 106.3579°W, depth 0.7 m, organic carbon content 1.13%, organic matter content 1.94%, sand 82.44%, clay 8.27%, silt 9.29%, stn 7: 23.2174°N, 106.3917°W, depth 3.7 m, organic carbon content 5.59%, organic matter content 9.62%, sand 10.78%, clay 37.54%, silt 51.68%, stn 9: 23.1904°N, 106.4121°W, depth 5.4 m, organic carbon content 1.41%, organic matter content 2.43%, sand 64.81%, clay 8.09%, silt 27.11%, and stn 10: 23.1815°N, 106.4214°W, depth 6.0 m, organic carbon content 1.2%, organic matter content 2.07%, sand 69.12%, clay 7.91%, silt 22.97%.