Gazia gazi Lowry & Springthorpe 2019
Creators: name: Bichang'A, Joshua Sese
name: Kioko, Esther N.
name: Liu, Hongguang
name: Li, Shuqiang
name: Hou, Zhonge
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Talitridae
Gazia
Gazia gazi

description: Gazia gazi Lowry & Springthorpe, 2019
(Figs 3, 16–19)
Material examined. Male 7.5 mm (NMK /INV/ AMP/0004) and female 8.5 mm (NMK /INV/ AMP/0005), English Point Beach, Mkomani, Mombasa County, Kenya, S 04.05763 °, E 039.68376 °, 4 m a. s. l., 29 th July 2018, J. Sese and G. Kioko; one male and three females (NMK /INV/ AMP/0006) same data as male 7.5 mm (NMK /INV/ AMP/0004). One male specimen was used for molecular analysis and the sequence was submitted to GenBank (MW 363128).
Ecological type. Beach hoppers supralittoral type, often burrowing in sand and leaf litter on the beach during low tide when temperatures are high. No Mangroves or other significant coastal vegetation was recorded at the collection site.
Diagnosis. Gazia gazi female can easily be identified by short antenna I reaching the base of article V of antenna II; antenna II shorter than half the body length; left mandible with five dentate incisor and four dentate lacinia mobilis; maxilliped palp article IV masked by palp article III; posterior margins of merus, carpus, and propodus of gnathopod II with tumescent hump; gnathopod II to pereopod V with oostegites, longer than wide, and with 6–11 fine smooth tipped setules; epimera II–III with vertical slits just above the ventral margin, 40 and 44 respectively; uropod I outer ramus without marginal spines; telson with seven robust spines per lobe.
Description based on female (NMK/INV/AMP/0005), 8.5 mm (Fig. 3). Antenna I (Fig. 16A), short, reaching the base of peduncular article V of antenna II; peduncle with five articles; flagellum with three articles. Antenna II (Fig. 16B), 0.2 times as long as body length; peduncular article III wider and shorter than articles IV and V; article V longest, 1.5 times as long as article IV; peduncular and flagella articles with many small, robust setae; flagellum with 19 articles and 2.2 times as long as peduncular article V, last article (Fig. 16C) cone-shaped and bare.
Upper lip (Fig. 16D), ventral margin of the apex rounded and setulose; mandibular processes present and well developed. Lower lip (Fig. 16E), bilobed, apical and inner margins of the outer plate and central trough lined with fine setules. Left mandible (Fig. 16F), incisor five-dentate, lacinia mobilis four-dentate, with pappose setae; molar well developed, with an accessory pappose seta. Maxilla I (Fig. 16G), inner plate slender with two apical robust pappose setae; outer plate distal margin with nine robust setae of dentition formulae 5̅4̅5̅4̅2̅4̅3̅2̅3; one small articulate palp present. Maxilla II (Fig. 16H), inner plate distal margin with more than 11 smooth-edged blunt setae, four rugged edged setae on the ventral side, and one large subapical pappose seta; outer plate with more than 15 smooth-edged short setae and at least four rugged edged setae. Maxilliped (Fig. 16I), inner plate well developed, distal margin with three unequal sized stout teeth and pappose setae; outer plate exceeding palp article I, apical margin with robust setae; palp article II about 1.9 times as wide as long, with a well-developed distomedial lobe; palp article III longer than wide, with robust distal setae in two rows; article IV masked by palp article III distal setae.
Gnathopod I (Fig. 17 A–B), sexually dimorphic; coxa smaller than that of gnathopod II, ventral margin with seven small sharp spines; basis slightly enlarged towards the posterodistal end, anterior margin somewhat straight with seven setae, posterior margin slightly curved with one seta and two setae towards the base of the ischium; ischium posterior margin with six robust setae; posterior margins of the carpus, merus, and propodus without tumescent hump-like in their males instead, the margins well developed consisting of not less than seven bifid setae on the three articles; carpus about 1.7 times as long as propodus and with six robust bifid setae on the anterior margin; propodus reduced posterodistally, palm reduced, dactlylus cuspidactylate and attenuated distally. Gnathopod II (Fig. 17 C–D), sexually dimorphic; coxa ventral margin with 12 small sharp spines; basis proximally reduced and slightly expanded, anterior margin with 15 short sharp setae, posterior somewhat straight and bare; ischium longer than short with three robust setae on the posteroventral end; merus, carpus, and propodus posterior margins with well-modified tumescent humps; merus posterior margin with 11 robust bifid setae from the mid of the posterior margin to the base of the tumescent hump; carpus about 1.6 times as long as merus, anterior margin with three robust setae, posterior margin with one robust seta at the base of the tumescent hump; propodus longer than wide, with 15 robust bifid setae at the base of the tumescent hump, palm reduced, with a smooth anterior margin, anteroventral end (at the base of dactylus) with at least six robust setae, posterior margin with a bundle of three robust setae, dactylus subequal in length to palm.
Pereopods III̅VII (Fig. 18 A–E), cuspidactylate and similar in appearance to the male. Pereopod III (Fig. 18A), considerably longer than pereopod IV; coxa wider than deep, with ten short, stout spines on the ventral margin; basis with five and six robust setae on the anterior and posterior margins respectively, slightly enlarged distally; ischium, 2.7, 1.5, and 1.1 times as long as merus, carpus, and propodus respectively; anterior margins of merus, carpus, and propodus, lined with stout bifid setae. Pereopod IV (Fig. 18B), similar to pereopod III, dactylus shorter but wider anteriorly than that of pereopod III. Pereopod V (Fig. 18C), coxa bilobed, with five short spines on the ventral margin of the smaller lobe; basis, ovoid with small sharp setae distinct on dorsal and ventral margins, posterodistal lobe present, merus enlarged distally; propodus slender and long, 1.3 times as long as carpus and merus; dactylus slender and attenuated distally. Pereopod VI (Fig. 18D), coxa bilobed, posterior lobe posteroventral corner rounded, with seven short spines; basis ovoid, about 1.4 times longer than wide; merus, carpus, and propodus lengths in the ratio 4: 5: 7; dactylus nearly 1.2 times as long as that of pereopod V. Pereopod VII (Fig. 18E), 1.6 times as long as pereopod III; coxa ovoid, ventral margin with four short setae; basis subcircular, posterior margin distinctly serrated, anterior margin with short spines, posterodistal lobe deep; merus, carpus, and propodus lengths in the ratio 5: 6: 7; dactylus (Fig. 18J), slender and longest of all pereopods.
Oostegites, present on gnathopod II to pereopod V, longer than wide, and with 6–11 fine smooth-edged setules only from the midpoint to the distal end; shortest but widest in pereopod V. Coxal gills present on gnathopod II and pereopods III–VII, longest in pereopod VI.
Pleopods I–III (Fig. 19 A–C), all well developed, biramous, subequal in length, and rami with numerous plumose setae; coupling hooks present at the distal end of the peduncle. Pleopod I (Fig. 19A), peduncle with one robust marginal seta; inner ramus with eight articles; outer ramus with nine articles. Pleopod II (Fig. 19B), peduncle with four robust marginal setae; both rami with eight articles. Pleopod III (Fig. 19C), peduncle with three robust marginal setae; inner and outer rami with eight and nine articles respectively.
Uropods I–II (Fig. 19 D–E), biramous; peduncles, about 1.3 times as long as both rami, with 13 and 12 robust marginal spines. Uropod I, inner ramus with five robust marginal spines and three apical spines; outer ramus without marginal spines but three robust apical spines. Uropod II inner ramus with two marginal spines and four apical spines; outer ramus with one marginal and four apical spines. Uropod III, (Fig. 19F) uniramous and the smallest of the three; peduncle with three robust marginal spines; ramus with two marginal spines and three-terminal spines.
Epimera II–III (Fig. 19 H–I), with 41 and 44 vertical slits just above the ventral margin, respectively. Telson (Fig. 19J), apically incised, bilobed, dorsal midline entire, with five bifid stout marginal setae and two stout bifid terminal setae per lobe.
Distribution. Kenyan coast, Gazi Beach (type locality) and English Point Beach, Mkomani (current study).
Remarks. A close comparison with Gazia gazi Lowry & Springthorpe, 2019 recorded from Gazi Beach, Kenya, revealed that the specimens from Mkomani, Kenya, belonged to Gazia by having: similar ecological type (beachhoppers); antenna I shorter than antenna II; four cuspidate left mandible lacinia mobilis; subchelate gnathopod I, with a well-developed tumescent hump only on the carpus and propodus posterior margins; bi-cuspidate pereopods III–VII; epimera II–III with slits just above the ventral margin; telson with spines in the range three to nine spines per lobe. The specimens resemble Gazia gazi Lowry & Springthorpe, 2019 in the male gnathopod II palm reaching 55% of the length of the propodus; four dentate lacinia mobilis on the left mandible (Fig. 12J); maxilliped palp article IV being veiled by palp article III distal setae (Fig. 12I); and similarity with pereopods III–VII (Fig. 14). Due to these resemblances, the specimens are presented as Gazia gazi (Figs 3 and 12–19). Gazia gazi is distinguishable from the South African G. ancheidos (Barnard, 1916), G. samroiyodensis (Azman, Wongkamhaeng & Dumrongro- jwattana, 2014) from Thailand, G. guadalupensis (Ciavatti, 1989) from the Caribbean Sea, and Madagascan G. itampolo (Lowry & Springthorpe, 2015) by having a distinctively ridged palm posterior margin in male gnathopod II (Fig. 13D).
Here we provide its female description, whose information was unknown from the original description (Lowry & Springthorpe 2019). On the same note, a link to the molecular sequences used in the study is provided (Table 1) and can be useful in other molecular studies.
Just as highlighted broadly, the incorporation of morphological and molecular data in species delimitation allows a high level of confidence, crucial for both biodiversity and ecological research (Beermann et al. 2018; Dayrat 2005; Orr et al. 2020; Padial et al. 2010). Therefore, to ensure an improved species discovery and description, taxonomy needs to be consolidative to keep up with the constantly rising demand for accurate biodiversity data.
Besides the Talitridae family, four more families have been registered from Kenya. They include Amphilochidae, with one species, Afrogitanopsis paguri (Myers, 1974); Aoridae, with two species, Globosolembos excavatus (Myers, 1975) and Grandidierella propodentata Moore, 1986; Oedicerotidae, with one species, Oediceroides wolffi Barnard, 1961; and Maeridae with one species, Quadrivisio bengalensis Stebbing, 1907 (Horton et al. 2019). Floresorchestia mkomani Bichang’a & Hou, sp. nov. is the first Floresorchestia species recorded from Kenya. So far, amphipods published from Kenya and East Africa are marine species collected from the coastal region; neither terrestrial nor freshwater species have been published. To ensure a clear exemplification of the amphipod diversity in Kenya, East Africa and the African continent, more research is recommended.
resorchestia species and Gazia gazi.
description: Published as part of Bichang'A, Joshua Sese, Kioko, Esther N., Liu, Hongguang, Li, Shuqiang & Hou, Zhonge, 2021, Two species of Talitridae (Crustacea, Amphipoda) from Kenya, pp. 331-358 in Zootaxa 4927 (3) on pages 350-356, DOI: 10.11646/zootaxa.4927.3.2, http://zenodo.org/record/4542178