Gonodactylellus lanchesteri ( Manning, 1967b )

Gonodactylellus lanchesteri ( Manning, 1967b)

( Fig. 6 View FIGURE 6 )

Gonodactylus lanchesteri Manning, 1967b: 11–13 , fig. 4 [ type locality Junghi Bay, Ibo Archipelago, Mozambique].— Cappola & Manning, 1995: 276.

Gonodactylus demanii .— Barnard, 1950: 862, fig. 3e.

Gonodactylellus lanchesteri .— Manning, 1995: 64–66, fig. 26.— Ahyong, 2005: 158–159.— Poupin et al., 2019: 5.

Material examined.KZN: SAMC-A015626 , 1 ♀ (TL 22 mm), Sodwana Six Mile Reef , 27°37’00.1”S 32°39’00.0”E, 26 Jul 1976, shallow intertidal, RW 16–17, coll GoogleMaps . R. Winterbottom, det. S. Ahyong ; SAMC-A015642 , 5 ♂ (TL 13–29 mm), 11 ♀ (TL 11–26 mm), Sodwana 2.5 km south of Boteler Point, 27°01’59.9”S 32°51’00.0”E, 30 Jul 1976, same as above GoogleMaps .

Other material examined. Mozambique: SAMC-A019435 , 3 ♂ (TL 14–27 mm), 2 ♀ (TL 22–28 mm), Vilankulos , 21°59’59.6”S 35°18’59.8”E, 22 May 1973, depth unknown, det. B. F. Kensley GoogleMaps ; SAMC-A19436 , 1 ♀ (TL 11.3 mm), Magaruque Island , 24 May 1973, det. B. F. Kensley. SAMC-A002205 , 1 ♀ (TL 27 mm), Mozambique islands , 1912, shallow intertidal, stat. 13.S, coll. K.H. Barnard.

Diagnosis. Ocular scales low, separate, rounded or subtruncate. Rostral plate basal portion with anterior margins transverse or sloping posterolaterally; anterolateral corners rounded; apical spine just longer than base. Mandibular palp 3-segmented. 5 epipods present. TS6–7 lateral process subequal, rounded to subtruncate. PLP1 endopod in adult males with lateral lobe on posterior endite. AS 1–5 unarmed posterolaterally. AS 6 with swollen carinae, apical spines occasionally absent on larger specimens. Telson broader than long; SM teeth with movable apices; IM and LT teeth short, blunt, apices rounded but sharper in smaller specimens; IM tooth of telson well-formed and extending posteriorly beyond IM denticles; LT tooth distinctly set off from margin or at least separated from margin by gap. Dorsal spination of telson variable; MD carina strongly inflated, with or without numerous dorsal spinules; SM carinae swollen, with several scattered dorsal tubercles or spinules; IM carinae with few scattered dorsal tubercles or spinules; 9–13 SM denticles; 1 or usually 2 IM denticles present. Uropodal exopod proximal segment with 10–12 movable spines and distal, ventral spine; inner margin of proximal segment and entire margin of distal segment setose. Uropodal endopod inner margin sinuous, entire margin setose.

Colour in alcohol. Faded, but with dark chromatophore positioned mid-dorsally on TS6, AS 1, 3–5. Dactylus blue with some blue pigmentation on raptorial claw. Telson and uropod with varying degrees of blue pigmentation. Several specimens examined by Manning (1967b) exhibit dark chromatophores scattered and concentrated in patches for TS8 and AS 1. Dark, transverse bands reported on the carapace and abdominal somites and lateral patches on TS6. Colour in life unknown.

Measurements. ♂ (n = 8) TL 13–29 mm, ♀ (n = 15) TL 11–28 mm. AWCLI 630–850. Barnard (1950) records specimens up to TL 40 mm.

Distribution and habitat. From Vietnam and Pakistan, Persian Gulf and Red Sea to Somalia, Kenya, Comoro Islands, Madagascar, Mozambique and South Africa; 0–13.5 m ( Ahyong 2005).

Remarks. Gonodactylellus lanchesteri is a relatively small species, distinguished from other congeners with spinules covering the telson by the uropodal endopod having the entire margin lined with setae. The similar G. demanii Henderson, 1893 , is distinguished from G. lanchesteri by only having a few setae proximally on the inner margin of the uropodal endopod, adjacent to articulation. Early accounts of the South African stomatopod fauna report occurrences of G. demanii from Mozambique ( Hansen 1926; Barnard 1950). However, these early identifications need verification since Manning’s (1967b) investigation into the G. demanii group in the Indo-West Pacific erected three new species, including G. lanchesteri . Moreover, the recent re-evaluation of records of G. demanii in the northwestern Indian Ocean has revealed that they represent a separate species, G. celosinus Ahyong, 2024 . Thus, G. demanii sensu stricto is restricted to the Bay of Bengal and does not occur in the western Indian Ocean (Ahyong 2024). In support of these findings, one of the specimens identified as G. demanii by Barnard (1950) from Mozambique Island has been re-examined herein and can be confidently identified as G. lanchesteri . This suggests that Barnard’s G. demanii was misidentified and those specimens in the Iziko collection can be considered G. lanchesteri .

Ahyong’s (2005) more recent report of G. lanchesteri is the first reliable account of the species from South Africa. The species is known for its variability in telson spinule ornamentation, which is illustrated herein using specimens reported on by Ahyong (2005). Typically, the telson carinae of males are more inflated, while the spinules of the telson are longer and sharper in females ( Fig. 6D–F, H View FIGURE 6 ). Furthermore, a greater number of telson spinules is observed for smaller specimens when compared to large adults. This loss of spinules with greater size has been recorded by Manning (1967b) and is hereby confirmed for the examined specimens.