Caecognathia alsalmiyah Khalaji-Pirbalouty & Al-Kandari 2023, sp. nov.
Creators: name: Khalaji-Pirbalouty, Valiallah
name: Al-Kandari, Manal Abdulrahman
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Gnathiidae
Caecognathia
Caecognathia alsalmiyah

description: Caecognathia alsalmiyah sp. nov.
urn:lsid:zoobank.org:act: 1CC9B429-7656-4D2F-8077-3B9116F5B96F
Figs 2–4
Type material. Holotype. ♂ (2.7 mm), Public Beach (Al-Blajat Beach) at Al-Salmiyah, Kuwait; 29°20’16.23”N; 48° 5’48.88”E; 15 February 2022; in compacted reef and coral rubble, 1–1.5 m coll. V. Khalaji and M. Nithyanandan (ZMH-K-63974). Paratypes. 3 Ovi. ♀ ♀ (up to 3.6 mm); 11 pranizae (up to 1.6 mm); same data as holotype, (ZMHK-63975).
Diagnosis. Eyes large. Frontal border evenly rounded and serrated. Mandible with a smooth blade. Supraocular lobe well extended distally pointed with 3 cusps. Pereonite 3 with anterior constriction, posterolateral margins oblique, with 3 tubercles on each side. Pylopod with four articles, third article small, fourth article minute.
Description of male. Body length 2.7 mm, about 2.9 times as long as wide (Fig. 2 A).
Cephalosome (Figs 2 B, C, 4 A), about 1.6 times wider than long, with 3 fine tubercles and several fine seate laterally. Frontal border evenly rounded, anteriorly with irregular border and fine notches; dorsal sulcus shallowly narrower than width of frontal border, with 4 fine setae on each side. External scissura wide, shallow. Supraocular lobe long, distally pointed with 3 cusps. Eyes large, well developed, about 0.3 times as long as cephalosome length.
Pereonites 2–6 (Fig. 2 A) with small submarginal setae. Pereonites 2, 3, and 5 subequal in width, about 1.1 times as wide as cephalosome. Pereonite 1 immersed in cephalosome, not reaching lateral margin, partially obscured by pereonite 2 laterally. Pereonite 3 with anterior constriction, posterolateral margins with 3 tubercles. Pereonite 4 longer and narrower than pereonite 3, with anterior constriction; median groove present and posteriorly directed. Areae laterales present on pereonite 5. Pereonite 6 without lobi laterales; lobuii weak. Pereonite 7 dorsally visible, small with rounded posterior margin. Pleonites 1–5, epimera not visible dorsally, one pair of simple setae on each side posteriorly on all pleonites. Pleotelson (Figs 2 N, 4 D) 0.94 times as long as anterior width, covered in pectinate scales, lateral margins fringed with fine acute setae, anterolateral margins weakly convex, posterolateral margin weakly concave, mid-dorsal surface with 2 sub-median simple setae, posterolateral margins with 2 submarginal setae, apex with 2 long setae.
Antennula (Fig. 2 D) short, smaller than antenna, article 3 about 2 times as long as article 2; flagellum with 5 articles, about 1.4 times as long as peduncle article 3, articles 3–5, each bearing an aesthetasc. Antenna (Fig. 2 E) peduncle article 4, 1.3 times as long article 3; flagellum with 7 articles.
Mandible (Fig. 2 F) about 0.32 times as long as cephalosome width, strongly curved, with unarmed carina; incisor pronounced; blade present, smooth.
Maxilliped (Figs 2 G, 4 G) article 1 external margin fringed with fine, small setae; endite extended beyond article 2; external margins of articles 2–5 bearing 3, 6, 5 and 7 stout plumose setae respectively; article 5 with 3 simple setae distally.
Pylopod (Figs 2 H, 4 E, F) with 4 articles; article 1 about 1.7 times longer than wide, lateral margin with about 32 plumose setae, mesial and proximal margins with continuous fine setae, distal end with 5 setae; article 2, 1.7 times as long as wide, 0.15 times length of article 1, fringed with dense fine setae, 5 long simple setae distally; article 3 small, fringed with dense fine setae, about 1.5 times as long as wide, 0.35 times length of article 2; article 4 minute.
Pereopods 2–6 (Fig. 3 A – E) with numerous long simple setae on basis. Pereopods 2 and 3 (Figs 2 A, 2 B) similar in shape, with tubercles on ischium, merus and carpus inferior margins. Pereopod 4 (Fig. 3 C), shortest, basis with few tubercles on lateral surface and superior margin; ischium inferior margin with a prominent tubercle on interproximal margin and 5 smaller tubercles on inferior margin, 1 robust seta on superior margin. As illustrated Pereopod 5 (Fig. 2 D) similar to pereopod 6 (Fig. 3 E).
Pleopods 1–5 (Fig. 2 I – M) similar as illustrated. Pleopod 1 endopod and exopod with approximately 5 and 8 plumose marginal setae, respectively; endopod longer than exopod, about 2 times as long as wide; exopod 2.3 times as long as wide; sympodite mesial margin with 2 coupling hooks, lateral margin with 2 stout simple setae. Pleopod 2 endopod and exopod shape as in pleopod 1, distally with 4 and 7 plumose marginal setae, respectively; appendix masculina absent.
Uropod (Figs 2 N, 4 D), peduncle with 1 long seta mediodistally; endopod about as long as exopod, about 2.3 times longer than wide, fringed with 9–10 long plumose setae; exopod narrower than endopod with 9 long plumose setae.
Female. An ovigerous female figured (Figs 4 D, E).
Distribution. Only known from the type locality.
Hosts. Not known.
Remarks. Caecognathia alsalmiyah sp. nov. is similar to C. nieli Svavarsson, 2006 from New Zealand, as both species have an evenly rounded frontal border and a long and pointed supraocular lobe. However, the new species is distinguished from C. nieli in having fewer setae on pereonites and pereopods; 4-articulated pylopod (instead of 3), maxilliped article 2 with 3 plumose marginal seate (instead of 7). In addition, the new species differs from C. rhektos Kensley, Schotte & Poore, 2009, the only species reported from the western Indian Ocean (Mauritius Island, east of Madagascar), which has a cephalosome with small eyes; a mandible with smooth and straight blade; 3-articled pylopod, and a small and distally blunt and rounded supraocular lobe.
Etymology. The name refers to the type locality in the intertidal area of Al-Blajat Beach at Al-Salmiyah, Kuwait.
description: Published as part of Khalaji-Pirbalouty, Valiallah & Al-Kandari, Manal Abdulrahman, 2023, Three new species of temporary fish parasite, Gnathiid Isopods (Crustacea: Isopoda: Cymothoida) from Kuwait, pp. 24-38 in Zootaxa 5383 (1) on pages 26-30, DOI: 10.11646/zootaxa.5383.1.2, http://zenodo.org/record/10301486