Galathea noboya, Botha & Griffiths & Atkinson & Macpherson, 2025

Botha, Thomas P. A., Griffiths, Charles L., Atkinson, Lara J. & Macpherson, Enrique, 2025, The Galatheidae (Anomura: Galatheoidea) of South Africa, with a description of a new species, Zootaxa 5661 (3), pp. 330-350 : 338-341

Galathea noboya sp. nov.

( Figs. 4 , 7C, D )

Galathea nexa . — Doflein & Balss, 1913: 139 (not G. nexa Embleton, 1836 ).

Galathea dispersa . — Barnard, 1950: 486, fig. 91f–h; Kensley, 1981: 34 (list); Tirmizi & Javed, 1993: 67, fig. 29 (not G. dispersa Bate, 1859 ); Emmerson, 2016b: 443 (list).

Type material. Holotype: south of Mossel Bay , South Africa, 34°19’43.68”S, 22°11’44.23”E, 75 m, 20/05/2022, SAMC-A094807 , ♂ 8.3 mm . Paratypes: South Africa, 34°19’43.68”S, 22°11’44.23”E, 75 m, 20/05/2022, SAMC- A094807, 3 ♂ 4.1–5.3 mm, 2 ovig. ♀ 6.1 mm .

Other material examined. South Africa, 34°09’17.46”S, 22°48’37.32”E, 74 m, 01/05/2019, SAMC-A094743 , 3 ♂ 4.1–9.1 mm ; South Africa, 35°20’23.64’S, 21°38’12.12’E, 127 m, 15/05/2021, SAMC-A094753 , 1 ♂ 7.1 mm ; South Africa, 35°13”S, 21°19’18.00”E, 111 m, 22/03/1948, SAMC-A019511 , 13 ♂ 4.2–8.5 mm; 6 ♀ 5.0– 7.1 mm, 4 ovig. ♀ 5.1–5.9 mm ; South Africa, 34°36’02.16”S, 21°07’00.48”E, 75 m, 14/05/2021, SAMC-A094752 , 1 ♀ 7.5 mm ; South Africa, 34°01’53.64”S, 25°45’44.34”E, 49 m, 08/04/2022, SAMC-A094802 , 2 ♂ 8.6–8.8 mm, 3 ovig. ♀ 7.2–8.1 mm ; South Africa, 34°04”S, 25°59”E, 84 m, 25/11/1960, SAMC-A094547 , 8 ♂ 1.9–7.1 mm, 9 ♀ 1.8–7.7 mm ; South Africa, 34°15”S, 25°50’24.00”E, 108 m, 09/02/1962, SAMC-A094546 , 1 ovig. ♀ 4.8 mm; South Africa, 29°46”S, 31°16’58.80”E, 130 m, 23/04/1958, SAMC-A094545 , 1 ♂ 7.7 mm ; South Africa, 29°53”S, 31°06”E, 183 m, 01/03/1963, SAMC-A012027 , 9 ♂ 3.3–6.3 mm, 5 ♀ 3.8–5.6 mm ; South Africa, 35°12”S, 22°11”E, 120 m, 24/05/1973, SAMC-A094539 , 1 ♂ 3.0 mm, 1 ♀ 4.5 mm, 1 ovig. ♀ 5.7 mm ; South Africa, 34°22’48.00”S, 23°21”E, 108 m, 20/09/1993, SAMC-A094562 , 4 ♂ 4.0– 7.4 mm, 1 ovig. ♀ 6.1 mm ; South Africa, 33°29’58.20”S, 27°13’52.68”E, 40 m, 29/08/1901, SAMC-A0919 , 5 ♂ 5.4–7.8 mm, 2 ♀ 4.6–8.1 mm ; South Africa, 33°49’59.88”S, 25°46’00.12”E, 37 m, 24/10/1898, SAMC-A0920 , 1 ♂ 10.0 mm, 1 ovig. ♀ 5.2 mm (dry specimens) ; South Africa, 34°14’51.00”S, 18°30’01.80”E, 42 m, 08/06/1900, SAMC-A0922 , 3 ♂ 5.9–9.7 mm, 1 ♀ 6.1 mm (dry specimens) ; South Africa, 33°25’39.72”S, 27°05’36.96”E, 40 m, 06/08/1901, SAMC-A0923 , 4 ♀ 5.9–7.4 mm (dry specimens) ; South Africa, 30°47’13.92”S, 30°34’50.88”E, 91 m, 14/03/1901, SAMC-A0924 , 2 ♀ 7.4 mm (dry specimens) ; South Africa, 29°21’02.88”S, 31°51’39.96”E, 113 m, 30/01/1901, SAMC-A0925 , 1 ♂ 6.2 mm (dry specimens) ; South Africa, 34°04’00.12”S, 25°07’59.88”E, 42–64 m, 26-28/04/1906, SAMC-A0930 , 2 ♂ 4.6–7.3 mm ; South Africa, 34°04’59.88”S, 22°13’59.88”E, 38 m, 24/06/1898, SAMC-A0931 , 1 ♀ 7.6 mm, 1 ovig. ♀ 7.2 mm (dry specimens) ; South Africa, 33°20’46.32”S, 27°23’01.32”E, 60 m, 27/08/1901, SAMC-A0932 , 1 ♀ 6.3 mm ; South Africa, 32°57’16.92”S, 28°05’13.92”E, 37 m, 11/07/1901, SAMC-A0933 , 1 ♂ 7.3 mm, 1 ♀ 7.4 mm ; South Africa, 33°13’59.88”S, 27°57’59.40”E, 90 m, 15/07/1901, SAMC-A0936 , 1 ♂ 6.1 mm, 1 ovig. ♀ 3.7 mm ; South Africa, 28°59’59.64”S, 31°46’26.40”E, 24 m, 08/02/1901, SAMC-A0937 , 2 ♂ 5.4–5.7 mm, 2 ♀ 6.9–8.8 mm (dry specimens) ; South Africa, 29°50’03.98”S, 31°14’08.99”E, 135 m, 05/02/2021, SAMC-A094775 , 1 ♀ 3.1 mm ; South Africa, 29°50’03.98”S, 31°14’08.99”E, 135 m, 05/02/2021, SAMC-A094775 , 2 ♀ 2.3–3.1 mm ; South Africa, 29°50’03.98”S, 31°14’08.99”E, 135 m, 05/02/2021, SAMC-A094786 , 1 ♂ 2.5 mm ; South Africa, 29°50’03.98”S, 31°14’08.99”E, 135 m, 05/02/2021, SAMC-A094776 , 1 ♂ (carapace missing), 3 ♀ 1.4–2.4 mm ; South Africa, 29°50’03.98”S, 31°14’08.99”E, 135 m, 05/02/2021, SAMC-A094781 , 3 ♂ 2.5–4.5 mm .

Etymology. From the Xhosa word noboya, which means ‘fluffy’, referring to the ‘fluffy’/setose nature of the chelipeds.A Xhosa word is used as this is the most spoken language in the Eastern Cape, which is where this species is most prominent.

Description. Carapace: Slightly longer than broad, with transverse ridges bearing short, dense plumose setae and few long setae. Cervical groove distinct, bifurcated laterally. Several transverse ridges; 2 epigastric ridges, anterior ridge interrupted medially by (2)–3 pairs of epigastric spines, posterior ridge scale-like; 3 protogastric ridges, anterior ridge laterally interrupted, convex medially, with 1 parahepatic spine on each side, median ridge convex medially, with pair of long medial setae, interrupted laterally, posterior ridge short, scale-like; 2 mesogastric ridges, anterior ridge uninterrupted, does not extend to lateral margins, posterior ridge interrupted; 3 metagastric ridges, anterior and median ridge uninterrupted with scales between them, not extending laterally to anterior branchial region; posterior ridge short, uninterrupted, also not extending laterally; (2)–4 small hepatic spines near anterolateral spine. Anterior branchial region with (4)–5 distinct short ridges, 1 anterior branchial spine on each side. Mid-transverse ridge uninterrupted, concave medially, preceded by cervical groove. Posterior branchial region with 9 transverse ridges, 4 ridges uninterrupted, scales between some ridges. Lateral margins slightly convex, with 9 spines: 2 spines in front of and 7 behind anterior cervical groove; anterolateral first, well-developed, second small, at midlength between anterolateral and anteriormost spine of branchial margin, small spine between first and second; 3 spines on anterior branchial region, and 4 spines on posterior branchial region, posterior one small. Small spine on frontal margin between lateral limit of orbit and anterolateral spine; infraorbital margin with 2 spines, one well-developed, the other small. Rostrum 1.6 as long as broad, length 0.5 postorbital carapace length, breadth 0.3 that of carapace; dorsal surface slightly concave; distalmost lateral incisions 0.3 distance between proximal-most lateral incisions; rostrum with several scales and setae, pointing down proximally, lateral margin with 4 deeply incised sharp teeth, decreasing in size anteriorly.

Pterygostomian flap unarmed, rugose, ridges with short setae, anterior margin angular.

Thoracic sternum: As long as broad, lateral limits diverging posteriorly. Sternite 3 2.3 times wider than long; anterior margin serrated with median notch; sternite 4 3.2 times wider than sternite 3. Numerous scales on sternite 4.

Pleon: Pleonites 2 and 3 with 3 transverse ridges on tergite, anterior and posterior ridge uninterrupted, medial ridge interrupted laterally; pleonite 4 with 1 uninterrupted ridge anteriorly and laterally interrupted ridge with scales in between; pleonite 5 with short mesial ridge anteriorly and 1 uninterrupted ridge posteriorly; pleonite 6 with 2 medially interrupted ridges. Males with G1 and G2.

Eye: Ocular peduncle 0.7 times as long as broad, maximum corneal diameter 0.5 rostrum width.

Antennule: Article 1 with 3 well-developed spines, distomesial and distodorsal spines subequal, large distolateral spine with long, fine setae. Ultimate article with tuft of fine setae on distodorsal margin.

Antenna: Article 1 with well-developed ventral distomesial spine exceeding distal margin of article 3. Article 2 with 2 well-developed distal spines, distomesial spine larger, pointing mesially, distolateral spine almost reaching distal margin of article 3. Article 3 with distomesial spine, article 4 unarmed.

Mxp3: Ischium with 2 well-developed distal spines on flexor margin, extensor margin with small distal spine; crista dentata with 24–25 denticles. Ischium 0.8 length of merus; merus flexor margin with 2 spines, proximal well-developed, distal one small, extensor margin with small distal spine. Carpus unarmed. All segments covered in long, fine setae.

P1: (2.4–)3.0 times carapace length, covered in short, dense plumose setae and fine setiferous scales. Merus 0.7 times carapace length, 1.7 times carpus length, with spines arranged in rows, dorsomesial and distal spines well-developed. Carpus 0.7 length of palm, 1.2–(1.5) times longer than broad, dorsal and lateral margin with row of spines, mesial margin with several spines, second spine massive. Palm 1.8 times longer than wide, lateral and mesial margins convex, both margins with row of spines, dorsolateral row extending onto fixed finger. Fingers 0.6–(0.7) times length of palm, curving outwards with gaping appearance, mesial margin of moveable finger with large tooth proximally and several spines reaching halfway along lateral margin.

P2–4: Moderately slender, with long plumose setae and several setiferous scales. P2 (1.6–)1.9 times carapace length, merus successively shorter posteriorly (P3 0.9 length of P2, P4 0.8 length of P3); P2 merus 0.6 times carapace length, 3.6 times longer than broad, 1.3 times longer than propodus; P3 merus 2.8 times longer than broad, 1.1 times longer than P3 propodus; P4 merus 2.5 times longer than broad, as long as P4 propodus; extensor margin of P2–3 merus with row of 7–9 spines, distalmost spine largest, P4 with 1 distal spine; flexor margin with 2 distal spines, followed by several eminences; P4 lateral margin with 2 spines. P2–3 carpus with 3–4 spines on extensor margin, with 2 subequal distolateral spines, P4 with 2 subequal distal spines; P2–4 carpi with 1 distal spine on flexor margin. P2–4 propodus 4.5–5.3 times longer than broad; extensor margin unarmed; flexor margin with 5–6 movable spines. P2–4 dactyli 0.6–0.7 length of propodi, distally ending in large, curved spine, flexor margin with 5 slender movable spines.

Epipods on P1–3.

Variation. Some specimens with short, broad rostrum 1.1–1.3 times as long as broad. Rostrum occasionally bearing 5 lateral spines instead of 4. Several specimens with 2 parahepatic spines instead of 1. Mxp3 occasionally with 3 spines instead of 2. Rarely 2 protogastric ridges present and not 3. Occasionally fewer transverse ridges on posterior branchial margin. Some specimens have P1:carapace ratio as high as 3.4 and not 2.4 as reported from the holotype, with males and females often exhibiting dimorphic P1’s.

Coloration in life. ( Figs. 7C, D ). Ground colour of carapace and pleon orange with some scattered whitish spots, tips of lateral spines and rostrum brick-red ( Fig. 7C ). Posterior pleomere tergites lighter orange, tailfan whitish and orange. P1 brick-red with plumose setae. P2–4 orange, dactyli lighter orange. Eyes often green. Occasionally with a white, medial stripe on dorsal surface of carapace ( Fig. 7D ).

Global distribution. Endemic to South Africa.

South African distribution. From False Bay to Durban Bay, 24–183 m ( Fig. 6 ) .

Genetic data. COI, 16S, see Table 1.

Remarks. Galathea noboya sp. nov. is characterized by the combination of gastric ridges not scale-like, carapace lateral margin with small, but distinct spine between anterolateral spine and anteriormost spine of branchial margin, antennular basal article with three well-developed terminal spines, distomesial spine always distinct, although sometimes clearly smaller than others, no cardiac spines on carapace, four or more epigastric spines and epipod on P1–3 and P2–4 merus each with two spines at the distoflexor angle. The closest species is G. hydrae . Galathea noboya sp. nov. can easily be distinguished from G. hydrae as the new species has a dorsal branchial spine, four spines on posterior branchial margin instead of three (these characters were consistent in all specimens examined) and pleonites 2 and 3 with two-three transverse ridges behind anterior ridge instead on one only.

Although superficially similar to G. nexa , this species differs in the following aspects: Rostrum with several long and short setae scattered throughout, pleonites 2 and 3 with three uninterrupted transverse ridges and third pleonite with two/three uninterrupted transverse ridges behind anterior ridge, unlike G. nexa , which bears almost no setae on the rostrum and only has one uninterrupted transverse ridge on tergite behind anterior ridge. Lastly, in terms of coloration, G. nexa has characteristic blue spots on the pterygostomian flap (absent in Galathea noboya sp. nov.). Galathea noboya sp. nov. showed a genetic divergence value of 2.7–3.5% (COI) and 1.8–2.4% (16S) from G. nexa . Therefore, it can be concluded that G. nexa does not occur in South Africa and that the specimens identified as G. nexa by Doflein & Balss (1913) should be referred to Galathea noboya sp. nov. Moreover, upon inspection of the specimens of G. dispersa held in the Natural History Collections of the Iziko South African Museum, it can also be confirmed that all specimens previously identified as G. dispersa by Barnard (1950) and Kensley (1981) are in fact Galathea noboya sp. nov., as these specimens bear a parahepatic spine as well as a dorsal branchial spine (absent in G. dispersa ) and the Mxp3 merus has two spines on the flexor margin, not three or four. These specimens are also not G. hydrae , as suggested by Macpherson & Robainas-Barcia (2015) based on differences listed above between these two species. Thus, G. dispersa is found in the north-east Atlantic and Mediterranean Sea and is not present in South Africa.

Interestingly, this new species exhibits some sexual dimorphism, as males have large, broad chelipeds, whereas in females, the chelipeds are shorter and more slender ( Fig. 7C, D ). The white, median stripe on the dorsal surface of the carapace occurs in males and females and represents natural variation, as genetic analyses showed these individuals exhibit no differences from specimens without the white stripe.

Figures

FIGURE 4. Galathea noboya sp. nov., holotype, ♂, 8.3 mm (SAMC-A094807), south of Mossel Bay, SouthAfrica:A, carapace and anterior pleonites, dorsal view; B, sternal plastron, ventral view; C, cephalic region, showing antennular and antennal peduncles, ventral view; D, left Mxp3, lateral view; E, right P2, lateral view; F, right P3, lateral view; G, right P4, lateral view; H, left P1 (setae omitted), dorsal view. Scale bar: H = 4.0 mm; A–G = 2.0 mm.

FIGURE 6. Marine ecoregions in South African waters (Sink et al. 2019) with distribution of species in the genus Galathea superimposed.

FIGURE 7. Dorsal view of live specimens. A, Galathea labidolepta Stimpson, 1858, Kenton-on-sea, South Africa, ovig. ♀, 6.0 mm (SAMC-A066508); B, Galathea labidolepta Stimpson, 1858, Still Bay, South Africa, neotype, ♀, 5.9 mm (SAMC- A094746); C, Galathea noboya sp. nov., Still Bay, South Africa, ♂ 7.1 mm (SAMC-A094753); D, Galathea noboya sp. nov., Still Bay, South Africa, ♀ 7.5 mm (SAMC-A094752).