Scottolana tama, Gómez & Yáñez-Rivera & García-Vázquez & Armenteros, 2024

Gómez, Samuel, Yáñez-Rivera, Beatriz, García-Vázquez, Leonardo & Armenteros, Maickel, 2024, On some new species of Canuelloida Khodami, Vaun MacArthur, Blanco-Bercial & Martinez Arbizu, 2017 (Crustacea: Copepoda) from a shallow coastal lagoon in north-western Mexico, Zootaxa 5555 (4), pp. 497-534 : 500-512

publication ID	https://doi.org/ 10.11646/zootaxa.5555.4.2
publication LSID	lsid:zoobank.org:pub:C226D1ED-7EDC-490F-86E2-4A897306116F
persistent identifier	https://treatment.plazi.org/id/039A510A-FFDD-FFAC-FF18-FE98EB28FD99
treatment provided by	Plazi
scientific name	Scottolana tama
status	sp. nov.

Treatment

Scottolana tama sp. nov.

urn:lsid:zoobank.org:act:7C48B881-943C-4FEB-AE39-C9CD8F81950B

( Figs. 2–11 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 )

Material examined. Ovigerous ♀ holotype preserved in alcohol (ICML-EMUCOP-020223-01), ♂ allotype preserved in alcohol (ICML-EMUCOP-020223-02), three ♀ paratypes dissected and mounted on six, 14, and eight slides (ICML-EMUCOP-020223-03–05), one ♂ paratype dissected and mounted on seven slides (ICML-EMUCOP-020223-06), five ♀, one ♂ CV, and three ♀ paratypes (ICML-EMUCOP-020223-07), and two ♀ paratypes (ICML- EMUCOP-020223-08) preserved in alcohol; holotype, allotype and paratypes ICML-EMUCOP-020223-05–07 from the type locality (stn 8, see below), paratype ICML-EMUCOP-020223-08 from stn 7 (see below); February 2, 2023; Leonardo García-Vázquez leg.

Type locality. North-western Mexico, northern Sinaloa state, Ohuira Bay , stn 8 (25.64°N, 108.96°W), sand 57.26%, silt 25.67%, clay 17.08%, C org 2.84 GoogleMaps %.

Other sites. North-western Mexico, northern Sinaloa state, Ohuira Bay , stn 7 (25.66°N, 108.96°W; sand 16.23%, silt 59.54%, clay 24.22%, C org 2.24%); Ensenada del Pabellón lagoon, stn 4 (24.48°N, 107.65°W) [see Gómez Noguera & Hendrickx (1997)], clayish sediment, C org 1.29 µmol g-1 GoogleMaps .

Additional material preserved in alcohol. North-western Mexico, northern Sinaloa state, Ohuira Bay: one CIII (ICML-EMUCOP-020223-09; stn 1; 25.61°N, 109.03°W; sand 67.07%, silt 23.79%, clay 9.14%, C org 1.07%), one ♀, one ♀ and one CV, and three ♀ and one ♂ (ICML-EMUCOP-020223-10–12; stn 2; 25.6°N, 109.02°W; sand 92.22%, silt 6.03%, clay 1.86%, C org 0.37%), three ♀, and three ♀ (ICML-EMUCOP-020223-13–14; stn 4; 25.62°N, 108.98°W; sand 16.52%, silt 53.61%, clay 29.87%, C org 3.36%), one ♀, and two ♀ (ICML-EMUCOP-020223-15–16; stn 5; 25.6°N, 108.98°W; sand 47.88%, silt 37.99%, clay 14.12%, C org 2.19%), one ♀ and one ♂, and one ♀ (ICML-EMUCOP-020223-17–18; stn 6; 25.56°N, 108.98°W; sand 27.34%, silt 49.06%, clay 23.60%, C org 2.37%), three ♀, and five ♀ and one ♂ (ICML-EMUCOP-020223-19–20; stn 7; 25.66°N, 108.96°W; sand 16.23%, silt 59.54%, clay 24.22%, C org 2.24%), and three ♀, one ♂, and one CV (ICML-EMUCOP-020223-21; stn 8; 25.64°N, 108.96°W; sand 57.26%, silt 25.67%, clay 17.08%, C org 2.84), collected in February , 2023; six ♀, two ♂, and two CV, and seven ♀ (ICML-EMUCOP-020623-05–06; stn 1; 25.61°N, 109.03°W; sand 71.68%, silt 21.48%, clay 6.84%, C org 0.93%), two ♀, and three ♀ (ICML-EMUCOP-020623-07–08; stn 3; 25.64°N, 109.0°W; sand 41.93%, silt 40.88%, clay 17.19%, C org 1.49%), three ♀ and one ♂ (ICML-EMUCOP-020623-09; stn 4; 25.62°N, 108.98°W; sand 20.77%, silt 53.54%, clay 25.68%, C org 2.89%), one ♀ (ICML-EMUCOP-020623-10; stn 5; 25.6°N, 108.98°W; sand 30.62%, silt 52.75%, clay 16.62%, C org 1.67%), one ♀, and two ♀ (ICML-EMUCOP-020623-11–12; stn 6; 25.56°N, 108.98°W; sand 15.37%, silt 58.58%, clay 26.06%, C org 2.58%), three ♀ (ICML- EMUCOP-020623-13; stn 8; 25.64°N, 108.96°W; sand 41.42%, silt 38.45%, clay 20.12%, C org 2.48%); June 2 2023; Leonardo García-Vázquez leg. GoogleMaps

Additional material dissected. North-western Mexico, central Sinaloa state, Ensenada del Pabellón lagoon: one ♀ (ICML-EMUCOP-010591-64) mounted on four slides; May 5, 1991 (see above for some environmental variables) .

Etymology. The species is dedicated to the fond memory of our friend and colleague Sergio “Tama” Rendón Rodríguez † (Instituto de Ciencias del Mar y Limnología).

Differential diagnosis. Canuellidae . Caudal rami with seven setae arising (sub)distally of which one inner element (seta II) transformed into a strong spine with a conspicuous setule-like structure (tube-pore?). Antennule seemingly six-segmented, with second to fifth segments imperfectly separated. Antenna with eight-segmented exopod, and three-segmented endopod; EXP1–7 with one, EXP8 with four setae; ENP1 with two, ENP2 with four, ENP3 with seven elements. Mandibular EXP three-segmented, EXP1 with two, EXP2 with one, EXP3 with three elements; ENP two-segmented, ENP1 with three, ENP2 with eight setae. Maxillulary EXP one-segmented, with 11 setae. Maxillary ENP two-segmented. Maxilliped phyllopodial; syncoxa with one praecoxal seta, and three coxal endites bearing two, four and two setae, respectively; basis with two, ENP with 11 setae. Male P6 a triangular plate with one distal smooth seta, and genital area with two slender long elements with clawed distal part.

Description of female. Habitus ( Fig. 2A View FIGURE 2 ) semicylindrical; total body length measured from anterior tip of rostrum to posterior margin of caudal rami ranging from 860 µm to 1100 µm (mean= 1008.8 µm; n= 8), with maximum width at the posterior margin of cephalosome. General body shape largely as in S. antillensis . Rostrum ( Fig. 5E View FIGURE 5 ) not fused to cephalosome; large, triangular, with rounded tip; with one subapical sensilla on each side; no pore detected. First pedigerous somite free; first to fourth pedigerous somites of about the same width, with parallel lateral margins; surface of prosomites covered with minute denticles, with smooth posterior hyaline fringes. Urosome ( Figs. 2A View FIGURE 2 , 3A, B View FIGURE 3 ) tapering posteriad, consisting of fifth pedigerous somite, genital somite and third urosomite fused dorsally and ventrally forming genital double-somite (the latter slightly longer than wide, with lateral internal cuticular band indicating former division between somites and with genital area ( Fig. 3B View FIGURE 3 ) situated proximally in the middle of ventral surface), two free urosomites, and anal somite with rounded anal operculum and caudal rami; surface of urosomites covered with tiny denticles, with sensilla and pores as shown; hyaline posterior fringe of fifth pedigerous somite, genital double-somite, fourth and fifth urosomites plain, hyaline fringe of anal somite minutely incised and flanked by two transverse rows of spinules. Caudal rami ( Fig. 3A, B View FIGURE 3 ) as long as fifth and anal somites combined, slightly conical, slightly tapering posteriad; inner and outer margins nearly straight; with seven setae arising (sub)distally, homology of setae difficult to determine, most probably as follows: seta I and II displaced ventrally on inner margin, the former short and slender, the latter transformed into a strong blunt spine with a conspicuous setule-like structure (tube-pore?) ( Figs. 3B View FIGURE 3 , 4 View FIGURE 4 ); seta III long, displaced ventrally close to inner distal corner; seta IV dorsal to seta V, the former without, the latter with fracture plane; seta VI short and slender, close to seta V; dorsal seta VII biarticulate at base, close to inner distal corner. Female holotype with two multiseriate egg sacs with 11 eggs each.

Antennule ( Fig. 5A, B View FIGURE 5 ) presumably with six original segments. First segment unarmed, with two subdistal rows of long spinules ventrally; second to fifth segments imperfectly separated, with 28 setae in all of which eight biarticulate, and two (seemingly free) aesthetascs; sixth segment with 14 elements of which one biarticulate.

Antenna ( Fig. 5C, D View FIGURE 5 ) biramous. Basis unornamented. Exopod relatively shorter than endopod; eight-segmented; first-seventh segments with one, eighth segment with four pinnate elements. Endopod three-segmented; first segment with two, second segment with two medial and two distal setae as figured, third segment with six pinnate well-developed setae and one small, slender, bare element.

Mandible ( Fig. 6A, B View FIGURE 6 ) with well-developed gnathobase bearing multicuspidate teeth and one pinnate seta as shown. Basis large, with two inner subdistal pinnate setae. Exopod three-segmented, bent outwards, first and third segments shortest, middle segment longest; first segment with one proximal and one subdistal seta, second segment with one proximal element, third segment with three setae; all setae plumose. Endopod two-segmented; first segment larger, with three inner subdistal setae, second segment with eight distal elements as depicted.

Maxillule ( Fig. 6C–F View FIGURE 6 ) with praecoxa and coxa partially fused. Praecoxal arthrite with medial row of small spinules and with two surface setae, distally with eight spines and two setae as shown. Coxal endite with short row of subdistal spinules and six setae; with two long plumose epipodal setae. Basis with row of long inner spinules, seemingly with two ill-defined endites of which proximal with three, distal with five elements. Exopod large, slightly bent outwards, one-segmented; with five inner relatively short setae, five distal very long elements, and one outer reduced seta; all elements plumose. Endopod shorter than exopod, two-segmented; first segment larger, with five inner elements as shown; second segment with six plumose setae.

Maxilla ( Fig. 7A View FIGURE 7 ) with large praecoxa bearing two endites; proximal endite larger than distal, with three long pinnate elements and one small bare seta; distal endite with two pinnate setae. Coxa shorter than praecoxa; with two endites of which proximal somewhat shorter, each endite with subdistal small spinules and three setae as shown. Allobasis drawn out into strong unipinnate claw accompanied by five elements of which one a strong spinulose spine nearly as long as claw. Endopod two-segmented; first segment with five, third segment with four setae.

Maxilliped ( Fig. 7B View FIGURE 7 ) phyllopodial. Praecoxa and coxa fused forming syncoxa; with one —praecoxal— proximal seta, and thee —coxal— endites of which proximal with two (one unipinnate, one strongly spinulose), medial with four (two unipinnate, two strongly spinulose), distal with two unipinnate setae. Basis with slender long spinules along outer margin and small subdistal spinular ornaments as figured, with two unipinnate setae. Endopod one-segmented, as long as basis; with 11 setae arranged as follows: innermost element strongly spinulose, three pairs composed of one inner unipinnate seta and one strongly spinulose element each, and four outer plumose elements.

P1 ( Fig. 8A View FIGURE 8 ) with intercoxal sclerite transversely elongate. Coxa and basis with spinular ornamentation as figured, the former with inner long pinnate seta, the latter with outer pinnate seta and inner pinnate spine. Exopod three-segmented of which EXP1 largest; EXP1–2 with spinular ornamentation as shown, EXP3 seemingly without spinular ornamentation; EXP1 with outer spine, without inner armature; EXP2 with outer spine and inner seta; EXP3 with three outer spines, two distal elements (one distal outer spine, one distal inner seta), and two inner setae. Endopod with three segments of similar lengths, but ENP1 larger, ENP3 reaching beyond EXP3; ENP1 with long outer setules, with one proximal inner seta; ENP2 with strong outer spinules, with one medial inner seta; ENP3 with strong outer spinules, with two outer spines, two apical elements (one distal outer flagellate short spine, one distal inner seta), and two inner setae.

P2 ( Fig. 8B View FIGURE 8 ) with U-shaped intercoxal sclerite with two distal pointed tines. Praecoxa triangular, transversely elongate, with small spinules along distal margin. Coxa large, with spinular ornamentation as figured, with long distal inner setules, with inner pinnate seta. Basis with long inner setules, with anterior spinules close to insertion of endopod and with posterior small spinules close to insertion of exopod, with outer pinnate seta as long as EXP1 and EXP2 combined. Exopod three-segmented, as long as but inserted at a lower level than endopod so that exopod appears to be shorter than endopod; EXP1 and EXP2 subquadrate, EXP3 elongate, longest; EXP1 with patch of strong outer spinules, with longitudinal row of inner setules, and with coarsely incised distal inner hyaline frill, with outer spine, without inner armature; EXP2 with patch of strong outer spinules, with finely incised distal inner hyaline frill, with outer spine and inner seta; EXP3 with few outer spinules proximally, with three outer spines, two apical elements (one distal outer spine, one distal inner seta), and two inner setae. Endopod three-segmented; ENP1 shortest, with posterior row of minute spinules close to outer margin, with long inner setules, with distal outer long apophysis reaching beyond tip of ENP2, with inner seta; ENP2 with longitudinal row of strong spinules on distal outer long apophysis, the latter reaching proximal third of ENP3, with long inner setules, distal inner hyaline frill finely incised, with inner seta; ENP3 longest, without spinular ornamentation, with subdistal medial pore, with one outer spine, two distal elements (one distal outer spine, one distal inner spiniform element), and two inner setae.

P3 ( Fig. 9A View FIGURE 9 ) with intercoxal sclerite, praecoxa and coxa largely as in P2, the latter with inner pinnate seta. Basis with transverse row of small spinules close to insertion of endopod, outer seta visibly shorter than EXP1. Exopod three-segmented, relative length of exopod and endopod as in P2; EXP1 and EXP2 largely as in P2; surface ornamentation of EXP3 as in P2, with subdistal outer pore, with armature consisting of two outer, two distal elements (one distal outer spine, one distal inner spiniform element), and one inner seta. Endopod three-segmented; ENP1 shortest, with few outer strong spinules at base of outer distal apophysis, distal inner hyaline frill coarsely incised, with inner seta; ENP2 largely as in P2 but distal outer apophysis less developed, with inner seta; ENP3 longest, without spinular ornamentation, with subdistal medial pore, with one outer spine, two distal elements (one distal outer spine, one distal inner spiniform element), and one inner seta.

P4 ( Fig. 9B View FIGURE 9 ) with intercoxal sclerite as depicted. Praecoxa as in P2 and P3. Coxa with spinular ornamentation similar to that of P3, unarmed. Basis with spinular ornamentation as shown, with bare outer seta as long as EXP1 and EXP2 combined. Exopod three-segmented, relative length of exopod and endopod as in P2 and P3; EXP1 largely as in P2 and P3, with outer spine, without inner armature; EXP2 largely as in P2 and P3, with outer spine, with bare inner spiniform element visibly shorter than in P2 and P3; EXP3 with few subdistal outer spinules, with one outer spine, two distal elements (one distal outer spine, one distal inner spiniform element), and one inner spiniform element. Endopod three-segmented, relative length of segments as in P3; ENP1 with few medial spinules subdistally, outer distal apophysis poorly developed, distal inner hyaline frill coarsely incised, with inner short spiniform element; ENP2 largely as in P2 but distal outer apophysis somewhat less developed, unarmed; ENP3 longest, without spinular ornamentation, with subdistal medial pore, with one outer spine, two distal elements (one distal outer spine, one distal inner spiniform element), and one inner spiniform element.

Armature of swimming legs as in the differential diagnosis above.

P5 ( Fig. 9C View FIGURE 9 ) incorporated into somite, with four pinnate setae of different lengths as shown, outermost basal.

P6 ( Fig. 3B View FIGURE 3 ) represented by one seta on each side of genital field, the latter midventral in genital somite proximally, large, with paired copulatory pores covered by flaps; largely as in S. antillensis .

Description of male. Habitus ( Fig. 2B View FIGURE 2 ) semicylindrical, largely as in female except for genital and third urosomites separated; total body length measured from anterior tip of rostrum to posterior margin of caudal rami ranging from 800 µm to 940 µm (mean= 832 µm; n= 5). Urosome ( Figs. 2B View FIGURE 2 , 10A, B View FIGURE 10 ) tapering posteriad; consisting of P5-bearing somite, subquadrate genital somite, three free somites, and anal somite with caudal rami; with sensilla and pores as shown. General shape of caudal rami ( Fig. 10A, B View FIGURE 10 ) as in female; all setae displaced (sub)distally; seta I close to outer distal corner, ventral to seta II, the latter medially on dorsal surface; seta III long, arising close to inner distal corner; principal setae IV and V with fracture planes; seta VI slender, short, arising on inner distal corner; dorsal seta VII biarticulate, close to inner distal corner. Sexual dimorphism expressed in the unmodified condition of the caudal setae, A1, and P6.

Antennule ( Fig. 11A, B View FIGURE 11 ) chirocerate; seemingly eight-segmented. First segment unarmed, ventrally with set of long spinules distally; second to fifth segments imperfectly separated, with 22 setae and two aesthetascs as depicted; sixth segment short, with three setae; seventh segment globular, with corrugated pads ventrally, with seven setae as depicted; last segment as shown, with seven setae one of which modified.

Antenna and postantennal mouthparts, P1–P5 as in female.

P6 ( Figs. 2C View FIGURE 2 , 10B, C View FIGURE 10 ) sexually dimorphic, similar to that of S. antillensis ; each leg consisting of a triangular plate closing off genital pores, with distal patch of minute spinules, with one distal smooth seta; genital area with additional slender long elements as long as plates of P6, with clawed distal part.