Ampithoe olokumae, Alves & Neves & Johnsson, 2023

Alves, Jessika, Neves, Elizabeth G. & Johnsson, Rodrigo, 2023, New species of Ampithoe Leach, 1814 from Todos-os-Santos Bay, Bahia State, Brazil, Journal of Natural History 57, pp. 2006-2027 : 2008-2018

publication ID	https://doi.org/ 10.1080/00222933.2023.2281030
DOI	https://doi.org/10.5281/zenodo.10480097
persistent identifier	https://treatment.plazi.org/id/03FE9F3F-6A2E-7247-FE7E-FB6C300BFDA4
treatment provided by	Plazi
scientific name	Ampithoe olokumae
status	sp. nov.

Treatment

Ampithoe olokumae sp. n.

urn:lsid:zoobank.org:act:49F7BB4F-8AF5-46DA-B470-10114085E420

( Figures 2–6 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 )

Examined material

Holotype. 1 male, 5.0 mm. Yacht Club da Bahia, Salvador City, Todos-os-Santos Bay , Bahia State, - 12.999319S,- 38.530823W, depth 2 m, 10 December 2019; associated with sponge Clathria sp. UFBA 3205 . GoogleMaps

Allotype. 1 female, ovigerous, 4.1 mm. Yacht Club da Bahia, Salvador City, Todos-os-Santos Bay , Bahia State, - 12.999319S,- 38.530823W, depth 2 m, 10 December 2019; associated with sponge Clathria sp. UFBA 3335 . GoogleMaps

Paratypes. 1 male 4.0 mm. Yacht Club da Bahia, Salvador City, Todos-os-Santos Bay , Bahia State, - 12.999319S,- 38.530823W, depth 2 m, 10 December 2019; associated with sponge Clathria sp . UFBA 3336 GoogleMaps .

2 females 3.1–3.5 mm. Yacht Club da Bahia, Salvador City, Todos-os-Santos Bay , Bahia State, - 12.999319S,- 38.530823W, depth 2 m, 10 December 2019; associated with sponge Clathria sp . UFBA 3515 GoogleMaps .

1 male 4.0 mm. Yacht Club da Bahia, Salvador City, Todos-os-Santos Bay , Bahia State, - 12.999319S,- 38.530823W, depth 2 m, 10 December 2019; associated with sponge Clathria sp . UFBA 3450 GoogleMaps .

Etymology. The species name refers to Olokun, a deity of sea and health for some African religions common in Bahia State.

Diagnosis. Antenna 1 longer than antenna 2. Antenna 1 and 2 moderately setose. Mandibular palp thin and poorly developed on both mandibles. Gnathopod 1 shorter than gnathopod 2, propodus longer than carpus, palm very short and acute. Gnathopod 2 propodus palm acute, with rounded excavation, palmar corner defined by rounded and narrow process. Pereopod 3 and 4 stout, coxae 3–4 not surpassing more than 50% of basis 3–4. Pereopod 5 basis globose and wide, merus, carpus and propodus subrectangular. Uropod 3 peduncle with long distal seta, outer ramus shorter than inner one, with 3 conical denticles, outer ramus apical margin setose. Telson distal margin straight, covered by several setules.

Description. Antenna 1 longer than antenna 2, moderately setose, article 1 subequal in length to 2, dorsal margin with a long and a small posterior seta, ventral margin with proximal tuft of 3 small setae, a medial tuft with 1 small and 2 long setae, ventral corner with 2 long, 2 medium and 2 small setae. Article 2 is 1.4 times thinner than article 1, ventral margin with 4 sets of setae, increasing in size towards posterior corner; dorsodistal corner with 3 medium setae. Article 3 reaches ½ of article 2 length, dorsodistal corner with 3 long and a small seta, ventral margin with 3 sets of setae increasing in size towards posterior corner. Accessory flagellum absent. Flagellum 1/3 longer than peduncle, with 13 articles ( Figure 2 View Figure 2 ).

Antenna 2 moderately setose, slightly wider than antenna 1, article 1 and 2 subequal in length. Article 2 ventral margin densely setose, reaching ¼ of article 3 length. Article 3 reaches 2/3 of article 4 length, dorsal margin with 1 small and 3 medium setae, ventral margin densely setose. Article 4 dorsal margin with 4 sets of setae, ventral margin with 5 sets of setae increasing in size towards the posterior corner. Flagellum reaching 2/3 of peduncle length, with 10 articles ( Figure 2 View Figure 2 ).

Mouthparts. Upper lip globose twice longer than wide, apically setose. Lower lip outer plate notched, lateral notch 1.3 times longer than medial one, medial lobe setose, inner plate ovate and apically setose. Right mandible molar robust, incisor with 3 teeth, lacinia mobilis multicuspidate, accessory setal row with 5 multicuspidate setae; slender and small mandibular palp, article 1 subquadrate, article 2 twice longer than article 1, article 3 1.3 times longer than article 2, with 2 long apical setae. Left mandibular incisor with 4 teeth, lacinia mobilis multicuspidate stouter than right one, accessory setal row like the right mandibula. Maxilla 1 palp 2-articulated, article 1 subquadrate, article 2 apically rounded and expanded, more than 3 times longer than article 1, apical margin setose. Outer lobe subrectangular, with 6 stout and multicuspidated apical setae; inner lobe small, conical, with 3 long lateral setae, apical margin naked. Maxilla 2 outer plate 2.1 times longer than wide, covered by small setules, apical and inner margin with long plumose setae; inner plate 2.4 times longer than wide, covered by setules, inner and apical margins with plumose long setae. Maxilliped palp 4-articulated, article 1 conical, outer margin with 4 setae, article 2 is 3 times longer than article 1, inner margin densely setose, article 3 reaching 1/3 of article 2 length, apical margin densely setose; article 4 conical, with small apical seta; outer plate 2.4 times longer than wide, outer margin with 5 long setae, apical margin with 6 multicuspidate ones, inner margin with 7 serrated setae; inner plate 1.8 times longer than wide, apical and inner margins covered by simple setae ( Figure 3 View Figure 3 ).

Pereon. Gnathopod 1 coxa 1 anteroventral corner rounded and projected, ventral margin with 7 small setae; basis robust, 2.2 times longer than wide, anterior, and posterior margins with 2 long anterior setae each one, posteroventral corner with 1 small seta. Ischium subrectangular, more than 3 times smaller than basis, posteroventral corner with long seta. Merus 1.3 times longer than ischium, posterior margin with long setae, posteroventral corner with a medium and 2 long setae. Carpus twice longer than merus, anterior margin with an anterior set of 2 setae and a medial one, anteroventral corner with 2 long setae, posterior margin densely setose. Propodus subrectangular, 1.6 times longer than carpus, posteroventral corner with dense tuft of long setae, posterior margin setose with stout and slender setae, propodus palm acute, densely setose, extremely short, reaching less than 1/3 of posterior margin length. Dactylus 2.5 times longer than palm, inner margin serrated, facial margin with seta ( Figure 4 View Figure 4 ).

Gnathopod 2, coxa 2 subrounded, slightly longer than wide, ventral margin with 5 small setae, basis wider and stronger than gnathopod 1 basis, 1.7 times longer than wide, posterior margin with 6 setae, anterior margin with small seta, anteroventral corner rounded and produced. Ischium subrectangular 1.2 times wider than long, posteroventral corner with 2 small setae. Merus 1.6 times longer than ischium, posteroventral corner with tuft of setae, anterior margin with proximal set of 2 setae, a medial one, anteroventral corner with tuft of medium setae; propodus 1.6 times longer than carpus, anterior margin with a medial set of 2 setae, anteroventral corner densely setose, posterior margin with 4 plumose setae; propodus palm oblique, excavated, defined by projected process, densely setose with subquadrate teeth near the hinge of dactylus. Dactylus as long as palm, inner margin with 2 rectangular and conical proximal process, distally serrated with 4 small and slender distal setules, outer margin with proximal medium seta ( Figure 4 View Figure 4 ).

Pereopod 3, coxa 3 subrounded, 1.8 times longer than wide, ventral margin with setules; basis twice longer than coxa, posterior margin with 4 proximal long setae and 2 medium distal ones, anterior margin with 1 proximal long seta and 1 distal small seta. Ischium subquadrate as long as wide, posteroventral corner with small seta. Merus subrectangular, 1.3 times longer than ischium, posteroventral corner with 1 long and 1 small setae, anteroventral corner with 3 long ones. Carpus subrectangular, slightly shorter than merus, posterior margin with 2 sets of setae, anterior margin naked. Propodus 1.3 times longer than carpus, posterior margin with 2 medium setae and posterior set with a small and a long seta, anteroventral corner with dense tuft of setae, dactylus reaching ½ of propodus length ( Figure 5 View Figure 5 ).

Pereopod 4, coxa 4 subovate, 1.7 times longer than wide; basis 1.4 times longer than coxa, posterior margin with 3 long setae, posteroventral corner with 1 small seta, anterior margin with 4 long setae, anteroventral corner with 1 medium seta. Ischium subquadrate, as long as wide, posteroventral corner with 2 small setae. Merus 1.3 times longer than ischium, posterior margin with medial setae, posteroventral and anteroventral corners with long and small seta each one. Carpus 1.2 times thinner than merus, subrectangular, posterior margin setose, anterior margin naked. Propodus 1.6 times longer than carpus, posterior margin distally setose, ventral margin with stout seta, anteroventral corner setose, anterior margin with proximal medium seta, dactylus 1.4 times shorter than propodus ( Figure 5 View Figure 5 ).

Pereopod 5, coxa 5 lobated, as long as wide, ventral margin with small setae; basis globose, 1.3 times longer than wide, posterior margin with distal seta, anterior margin with 2 setae. Ischium subrectangular, 1.2 times wider than long, anteroventral corner with small seta. Merus twice longer than ischium, posteroventral corner with a long and a small seta, and anteroventral corner with small seta. Carpus subquadrate, subequal in length to merus, posterior margin with medial seta, posteroventral corner with tuft of setae, anterior margin with proximal seta, anteroventral corner with 2 small setae and 1 long seta. Propodus 1.3 times longer than carpus, posterior margin with 2 stout and small setae, posteroventral corner setose, anterior margin with distal long seta, anteroventral corner with tuft of long setae. Dactylus robust, reaching 1/3 of propodus length ( Figure 5 View Figure 5 ).

Pereopod 6 coxa 6 lobated, 1.5 times wider than long, basis 1.8 times longer than wide, posterior margin with proximal small seta, anteroventral corner with small seta; ischium as long as wide, reaching 1/3 of basis length, anteroventral corner with long seta; merus subrectangular twice longer than ischium, posterior and anterior margins with medial small seta on each, anteroventral corner with 2 seta and posteroventral corner with a single seta; carpus reaching 2/3 of merus length, posterior margin with set of 2 setae, anterior margin with a single seta, posteroventral corner with 3 setae and anteroventral corner with 4 setae. Propodus 1.7 times longer than carpus, posterior margin with set of 2 long setae, anterior margin with medial seta and 2 long and 2 small distal ones, posteroventral corner setose, anteroventral corner with small seta; dactylus with seta, reaching 1/3 of propodus length ( Figure 5 View Figure 5 ).

Pereopod 7, coxa 7 thin, twice wider than long; basis long, 3 times longer than wide, posterior margin with distal seta. Ischium subquadrate, as long as wide, anteroventral corner with long seta. Merus subrectangular, twice longer than ischium, posterior margin with medial small seta, anterior margin with medial small seta, anteroventral corner with a small and a long seta. Carpus reaching 2/3 of merus length, posterior margin with medial set of a long and a small seta, posteroventral corner with tuft of long setae, anterior margin with medial seta, anteroventral corner setose. Propodus 1.3 times longer than carpus, posterior margin with distal set of 2 long setae, posteroventral corner setose, anterior margin with medial seta, anteroventral corner with 2 long and 2 small setae. Dactylus reaching less than 1/3 of propodus length ( Figure 5 View Figure 5 ).

Urosoma . Uropod 1 peduncle subquadrate, twice longer than wide, inner margin with distal tuft of long setae, distolateral corner with small seta;outer ramus 1.4 times longer than inner ramus, distal margin with 4 small and 1 bigger stout seta; inner ramus inner margin with 2 sets of small setae, distal margin with 4 small and strong stout setae. Uropod 2 peduncle 1.6 times longer than wide, dorsolateral corners with small stout seta on each; outer ramus reaching 4/5 of peduncle length,with 1 small slender,4 small stout and 1 strong stout seta; inner ramus shorter than outer ramus, inner margin with set of a stout seta and a slender seta,distal margin with 3 small and 1 strong stout setae.Uropod 3 peduncle slightly longer than wide, outer ramus 1.3 times longer than inner ramus, subrounded, distally setose; inner ramus conical with 2 robust curved setae and a small curved one. Telson conical, 1.2 times longer than wide, reaching 2/3 of U3 peduncle length, lateral margins with one seta on each, distal margin straight with 2 cusps and densely setose ( Figure 6 View Figure 6 ).

Ecological notes. Ampithoe olokumae sp. n. is the first species of the genus associated with a sponge. The specimens were found in Clathria sp. washings, living together with other amphipods, tanaidaceans, and isopods. A great number of previously described Ampithoe species are found associated with algae and seagrasses, like A. ferox , A. hinatore , A. brevipalma , A. koreana , A. ramondi and A. thaix ( Chevreux 1901; Barnard 1925; Kim and Kim 1988; LeCroy 2000; Iwasa-Arai et al. 2021). Some other species are found in coral rubble, such as A. kaneohe and A. kava . Ampithoe hughesae is found on dead branching coral reefs ( Myers 2014). Some species are also found on abiotic substrates of sand and rocks, like A. guaspare , A. akuolaka , and A. sectimana ( Barnard 1970; Barnard 1979; Conlan and Bousfield 1982).

Remarks. Ampithoe olokumae sp. n. resembles A. ramondi recorded from Brazil by the male gnathopod 2 propodus palm with a rounded excavation and palmar corner projected. Nevertheless, even considering the wide range of A. ramondi populations across the globe, A. olokumae sp. n. is clearly different from A. ramondi by the male gnathopod 1 propodus palm very short and setose (while not so short and less setose in A. ramondi ), male gnathopod 1 merus distoventral corner entire (while bifid in A. ramondi ), male gnathopod 2 propodus palm with tooth near hinge of dactylus (while teeth absent in A. ramondi ) (Krapp-Schickel 1978) ( Table 1 View Table 1 ).

The new species also differs from the Brazilian congeners A. robustimana and A. marcuzzi by the following characteristics: (1) shape of male gnathopod 2 propodus less than twice longer than wide (while twice longer than wide on A. marcuzzi and A. robustimana ); (2) male gnathopod 2 propodus palm acute (while subtransverse in A. marcuzzi and A. robustimana ); and (3) gnathopod 1 and 2 propodus palm dissimilar (while similar in A. marcuzzi and A. robustimana ) ( Ruffo 1954; Andrade and Senna 2017) ( Table 1 View Table 1 ).

Ampithoe olokumae is also different from A. thaix , endemic to Brazil, by showing (1) male gnathopod 2 propodus palm excavated (while it is convex in A. thaix ); (2) palmar corner defined (while not defined in A. thaix ) and (3) telson distal margin straight (while convex in A. thaix ) ( Iwasa-Arai et al. 2021) ( Table 1 View Table 1 ).

The new species resembles the other congeners A. biszeli Özaydinli and Coleman, 2012 , A. eremitis Peart, 2007 and A. hughesae Myers, 2014 by showing: (1) antenna 1 longer than antenna 2; (2) gnathopod 1 shorter than gnathopod 2; (3) gnathopod 2 propodus palm with U-shaped excavation and palmar corner defined and well-produced. Nevertheless, A. olokumae sp. n. differs from A. biszeli by the shape of male gnathopod 1: merus posteroventral corner entire (while bifid on A. biszeli ); propodus palm extremely short and straight (while not so short and sinuous in A. biszeli ) ( Özaydinli and Coleman 2012) ( Table 1 View Table 1 ).

The new species also differs from A. eremitis by the (1) gnathopod 1 propodus palm short, not excavated, and covered with long setae (while not so short, slightly excavated and covered with scarse and small setae on A. eremitis ), (2) gnathopod 2 propodus less than twice longer than wide (while twice longer than wide in A. eremitis ), (3) pereopods 3– 4 coxae not reaching more than 70% of basis (while surpassing almost all bases in A. eremitis ) ( Peart 2007). Ampithoe olokumae sp. n. is also different from A. hughesae by the mandibular palp poorly developed (while well developed in A. hughesae ) and the male gnathopod 1 covered by dense and stout setae, without stout seta near palmar corner (while covered with slender setae, with a stout seta near palmar corner on A. hughesae ) ( Myers 2014) ( Table 1 View Table 1 )