Armandia sinaitica Amoureux, 1983

Parapar, Julio, Al-Kandari, Manal & Moreira, Juan, 2025, The genus Armandia Filippi, 1861 (Annelida, Opheliidae) on the coast of Kuwait and Saudi Arabia, Zootaxa 5728 (1), pp. 107-143 : 121-124

publication ID	https://doi.org/10.11646/zootaxa.5728.1.4
publication LSID	lsid:zoobank.org:pub:5F864A97-59BA-4972-92BD-137555D1FD27
persistent identifier	https://treatment.plazi.org/id/03B70F11-FFDD-FFDA-FF38-EF7C76DBFDC1
treatment provided by	Plazi
scientific name	Armandia sinaitica Amoureux, 1983
status

Treatment

Armandia sinaitica Amoureux, 1983 View in CoL

Figures 1 View FIGURE 1 , 11B View FIGURE 11 , 12–17 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 ; Table 1

Armandia sinaitica Amoureux, 1983a: 723-728 View in CoL , figs. 1.1.-1.5.

Armandia sinaitica Amoureux – Amoureux 1983b: 254 View in CoL .

Material examined. 1,312 specimens in one hundred and four samples collected in twenty-three localities along the littoral of Kuwait ( Fig. 1 View FIGURE 1 , Tab. 1).

Diagnosis. Parapodia biramous, with prechaetal lobe, ventral lobe and dorsal cirrus. Lateral eyespots anterior to parapodia on 12–15 chaetigers ( CH 6/7– CH 17/20)*. Branchiae from CH 2 to last chaetiger. Anal tube opening with ventral incision and provided with 3 pairs of marginal papillae, one pair of basal papillae and unpaired anal cirrus.

(*) But see Description and Remarks

Description. Complete specimens ranging from 6.0–13.0 mm in length and 0.4–1.0 mm in width for 28–36 chaetigers. Prostomium conical, palpode short and clavate ( Figs 13A View FIGURE 13 , 14B–D View FIGURE 14 , 17E View FIGURE 17 ). Prostomial eyes only seen in alive specimens ( Fig. 17D–E View FIGURE 17 ). One pair of ring-shaped nuchal organs ( Figs 13A View FIGURE 13 , 14A View FIGURE 14 , 17B, E View FIGURE 17 ); pharynx eversible with about 10 oral tentacles in a transversal row ( Figs 14E–F View FIGURE 14 , 17D–E View FIGURE 17 ). Parapodia biramous, with prechaetal lobe, ventral lobe and dorsal cirrus. Prechaetal lobe symmetrical, with a tip giving distal border a pointed appearance ( Figs 13C–F View FIGURE 13 , 15B–F View FIGURE 15 ). Lateral eyespots anterior to parapodia on 15 chaetigers ( CH 7– CH 21) ( Fig. 17D View FIGURE 17 ), circular, those of CH 7 and CH 15– CH 21 smaller than others. Simple, long capillary chaetae in two bundles; notochaetae longer than neurochaetae ( Figs 13C View FIGURE 13 , 15A View FIGURE 15 , 16D View FIGURE 16 ). Ventral groove deep, well defined along all body ( Figs 13B View FIGURE 13 , 16D View FIGURE 16 , 17F View FIGURE 17 ). Branchiae present from CH 2 to last body chaetiger ( Figs 13A–B View FIGURE 13 , 16C View FIGURE 16 ), long, almost reaching dorsal midline, not decreasing in length in posterior chaetigers but only in last ones ( Figs 13B View FIGURE 13 , 16C View FIGURE 16 , 17F View FIGURE 17 ). Anal tube delicate. Shape variable: 1) quadrangular and as long as width at base and as 3–4 last chaetigers ( Figs 13B View FIGURE 13 , 17F View FIGURE 17 ) or 2) barrel-shaped, up to 2–3 times as long as width at base and as long as last 4–5 chaetigers ( Fig. 16C View FIGURE 16 ), straight at base, laterally compressed, increasing width at dorsal midline, and tapering again towards distal end. Anal tube opened terminally and with ventral incision ( Figs 13B View FIGURE 13 , 16A, C–D View FIGURE 16 ). Posterior border provided with 4–6 pairs of marginal papillae of similar length, about as long ( Fig. 17F View FIGURE 17 ) or 0.5 ( Fig. 13B View FIGURE 13 ) to 0.33 times as long as anal tube length ( Fig. 16C View FIGURE 16 ); internal unpaired ringed (due to fixation?) anal cirrus about 3 times as long as anal tube length, and pair of basal papillae slightly longer and thicker than paired marginal papillae ( Figs 13B View FIGURE 13 , 16A–D View FIGURE 16 ).

Variation. Variations in the number of chaetigers, anal tube size and marginal papillae were observed in most samples. Still, they were most pronounced in specimens from Umm Al-Maradim Island ( November 2014), Al-Nuwaiseeb, Failaka Island and Masfat Al-Ahmadi ( December 2014), as well as Aushairij ( February 2015). Furthermore, smaller specimens exhibit a highly contracted anal tube, revealing only the marginal papillae ( Figs 16E–F View FIGURE 16 , 17A, C View FIGURE 17 ). Prostomial eyes were only observed in live specimens ( Fig. 17D–E View FIGURE 17 ).

Distribution / Habitat. Armandia sinaitica was the most abundant species in the studied material from Kuwait and was present in most of the sampled localities associated with different types of substrates ( Tab. 1). Wehe & Fiege (2002) consider this species endemic to the Arabian Peninsula because of the only two existing previous reports by Amoureux (1983a, b). However, the abundance of this species in Kuwait and the lack of earlier records suggest possible misidentifications with A. intermedia .

Remarks. Armandia sinaitica was originally described from the Gulf of Aqaba (Red Sea; Amoureux, 1983a). The Kuwait specimens agree well with the main diagnostic characters of the species ( Amoureux 1983a): 1) 36 to 42 chaetigers (including small specimens), 2) branchiae from CH 2 to last chaetiger, 3) 12–15 pairs of lateral eyespots beginning in CH 6/7, 4) anal tube shape and features of marginal papillae.

Armandia sinaitica clearly differs from the other species found in Kuwait in the shape and size of the anal tube and the presence of two types of anal papillae (marginal and basal). Other similar species are A. casuarina Moreira & Parapar, 2017 , A. mariacapae Moreira & Parapar, 2017 and A. opisthoculata Moreira & Parapar, 2017 from Lizard Island (Great Barrier Reef). Armandia casuarina mostly differs from A. sinaitica in having one pair of basal papillae that are provided each with about 15 small, digitiform papillae; in addition, in A. casuarina the unpaired anal cirrus is thick at base and slightly tapered distally and the posterior margin of the anal tube bears at least 6 pairs of alternating short and elongate papillae, one of the dorsal most inflated and longer than others ( Moreira & Parapar 2017: fig. 5B-C). Armandia opisthoculata resembles A. sinaitica in the shape of anal tube papillae but the basal papillae and the anal tube are shorter, and the latter also shows large spots of dark pigmentation in the distal ventral surface ( Moreira & Parapar 2017: figs 7G-I, 8D-F). Armandia mariacapae is the closest species to A. sinaitica but differs in having more marginal papillae (10 pairs vs 4/6 pairs) and basal marginal papillae that are provided with an inflated distal end ( Moreira & Parapar 2017: fig. 6G).

The other Armandia species previously reported in the Arabian Gulf are A. intermedia ( type locality: Senegal), A. lanceolata ( type locality: Sri Lanka) and A. leptocirris ( type locality: Philippines) ( Fig. 12 View FIGURE 12 ; see Fauvel 1911, 1918; Wesenberg-Lund 1949; Mohammad 1971, 1980; Fiege 1992; Parapar et al. 2021b). Armandia sinaitica differs from A. intermedia and A. leptocirris in bearing more chaetigers (36–42 vs 27–29 and 34, respectively); A. leptocirris bears 10–11 pairs of marginal papillae that are much smaller than those of A. sinaitica and lacks paired basal papillae, and A. lanceolata has a smaller anal tube that bears only one type of papillae ( Eibye-Jacobsen 2002: fig. 6C). Armandia intermedia was originally described from the coast of Senegal (W Africa, Atlantic Ocean; Fauvel 1902) ( Fig. 12 View FIGURE 12 ) and has been reported later across the world in different habitats, from western Africa to the Red Sea and NW Australia and in the Pacific Ocean ( Japan and New Caledonia) ( Day 1967). The anal tube of this species is tubular, annulated, about 0.66 times as long as wide and provided with two types of papillae and anal cirrus. These features are shared by several species of Armandia (e.g. A. maculata Webster, 1884 , A. laminosa Parapar & Moreira, 2015 , A. paraintermedia Parapar & Moreira, 2015 ) and therefore it is likely that some records of A. intermedia may correspond to other species.