Maratus nemo, Schubert, 2021

Schubert, Joseph, 2021, Maratus nemo: A new wetland species of peacock spider from South Australia (Araneae, Salticidae, Euophryini), Evolutionary Systematics 5 (1), pp. 71-80 : 71

publication ID	https://dx.doi.org/10.3897/evolsyst.5.64922
publication LSID	lsid:zoobank.org:pub:62D4C102-1CB9-4F5A-A056-2CCD5FB1B466
persistent identifier	https://treatment.plazi.org/id/62D4C102-1CB9-4F5A-A056-2CCD5FB1B466
taxon LSID	lsid:zoobank.org:act:62D4C102-1CB9-4F5A-A056-2CCD5FB1B466
treatment provided by	Evolutionary Systematics by Pensoft
scientific name	Maratus nemo
status	sp. nov.

Treatment

Maratus nemo sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Material examined.

Holotype male (SAM NN30706) from Australia, South Australia, Mount Burr Swamp , 9.5km SSE of Mount McIntyre, 37°36'22.43"S, 140°33'15.92"E, 2 Nov 2020, hand collected, S. Holliday. GoogleMaps

Paratype male (SAM NN30707) from Australia, South Australia, Mount Burr Swamp , 9.4km SSE of Mount McIntyre, 37°36'19.91"S, 140°33'17.85"E, 2 Nov 2020, hand collected, S. Holliday GoogleMaps .

Two paratype males (SAM NN30708, NN30709), one paratype female (SAM NN30710) Edge of South Australian and Victorian Border near Topperwein Native Forest Reserve, 14.1 km E of Nangwarry, 37°32'22.05"S, 140°58'23.34"E, 2 Nov 2020, hand collected, S. Holliday GoogleMaps .

Etymology.

The specific epithet refers to the colouration of the male of this species which resembles that of the character Nemo in the 2003 Walt Disney film 'Finding Nemo’ - to be treated as a noun in apposition.

Diagnosis.

Males of Maratus nemo share some similarities to members of the Western Australian Maratus personatus group ( Otto and Hill 2019; Otto and Hill 2021) in having the anterior ocular area ornamented with coloured scales, so as to form a ‘mask’, and in lacking opisthosomal colouration or flaps. It is thus tentatively placed in this species group (see Girard et al. 2021; Otto and Hill 2021; and Schubert 2020 about the tentative nature of subgeneric clades within Maratus ). Maratus nemo , however, can be readily separated from members of this species group and all other congeners by the following combination of characters: bright orange field of scales covering the clypeus and anterior ocular region (Figs 1A-F View Figure 1 , 2A-D View Figure 2 , 6A-D View Figure 6 ) light covering of fine white setae on the carapace, legs, and mostly glabrous dorsal opisthosomal plate (Figs 1A-F View Figure 1 , 2A-D View Figure 2 , 6A-D View Figure 6 ); relatively compact embolic disc by which the inner and outer rings of the embolus are in close contact or fused to form a single heavy apex (Fig. 3A-C View Figure 3 ); dark lateral sclerite proximal to the embolus; distinct thick extension or flange along the proximal arc of embolus (Fig. 3A View Figure 3 ). Females of M. nemo are similar to other Maratus females and identification may not be possible without association with a male.

Description.

Male (Holotype): Carapace dark brown, almost black with light covering of white setae; more densely covered at lateral and posterior slopes (Fig. 1A-F View Figure 1 ). Ocular quadrangle region covered thickly in bright orange scales and interrupted by two tracts of white scales behind each AME (Figs 1A-F View Figure 1 , 2A-D View Figure 2 ). Thin marginal band of white setae present at rim of carapace (Fig. 1A-F View Figure 1 ).

PME closer to PLE than to ALE. Surface surrounding AME and ALE and clypeus thickly covered with short, bright orange scales (Fig. 1A-F View Figure 1 ). Chelicerae dark brown and glabrous. Coxae and endites pale, labium dark brown and glabrous. Sternum dark brown with light covering of fine, white setae (Fig. 2C View Figure 2 ).

Dorsal opisthosoma dark brown and indistinctly marked with light covering of white scales. Border of dorsal opisthosoma more thickly covered with white scales (Fig. 1A-F View Figure 1 ). Colular tuft of white setae situated above black spinnerets (Fig. 8C View Figure 8 , worn in Fig. 1A-F View Figure 1 . See variation section). Ventral opisthosoma dark brown and scattered with short, white setae (Fig. 2C View Figure 2 ). Opisthosoma lacking any form of opisthosomal flaps.

Legs I and II subequal in length, legs III and IV longer, legs III longest. Integument of each leg dark brown with alternating rings of pale, yellowish cuticle; more prominently so on tarsal and metatarsal surfaces and coxae. Each leg with an incomplete cover of white setae (Fig. 1A-F View Figure 1 ). Dorsal pedipalp distinctly ornamented with prominent fringes of long white setae proximal to cymbium, bright orange setae on cymbium, and grey setae distally (Figs 1A-F View Figure 1 , 2C, D View Figure 2 .). Relatively large male palpal bulb with retrolateral sperm duct loop, large retrobasal tegular lobe, finger-like retrolateral tibial apophysis with light dentition (Fig. 3A-C View Figure 3 ). Relatively compact embolic disc of left pedipalp coiled anticlockwise, apices of inner and outer rings of embolus in close contact or fused to form a single heavy apex; distinct thick extension or flange along the proximal arc of embolus (Fig. 3A View Figure 3 ). Heavily sclerotized cuticle on tegulum prolaterally below embolic disc (Fig. 3A-C View Figure 3 ).

Female (Paratype): Ocular quadrangle region dark brown with light cover of light brown and off-white setae (Fig. 4A-F View Figure 4 ); rear slope of carapace with thicker covering (Fig. 4A, B, D, E View Figure 4 ). Lateral slopes of carapace light brown and glabrous (Fig. 4A, D View Figure 4 ).

Anterior eyes ringed with white and red-brown scales. Long white setae project downwards from below AME forming triangular shape (Figs 4A-D, F View Figure 4 , 5A View Figure 5 ). Clypeus lightly covered with short, white setae. Chelicerae dark brown and glabrous. Coxae pale, endites and labium dark brown, translucent and mostly glabrous. Sternum dark brown with light covering of fine, white setae (Fig. 5C View Figure 5 ).

Dorsal opisthosoma dark brown with incomplete cover of off-white and dark brown setae, otherwise mostly glabrous (Fig. 4A-F View Figure 4 ). Colular tuft of white setae situated above spinnerets (Fig. 4A, E View Figure 4 ). Lateral and ventral opisthosoma light brown and marked irregularly with dark spots (Fig. 5B, C View Figure 5 ).

Legs I and II subequal in length, legs III and IV longer, legs III longest. Each leg with incomplete cover of off-white and brown setae, integument below light brown and translucent (Fig. 4A-F View Figure 4 ). Pedipalps light brown and translucent with incomplete cover of white setae. Epigynum with pair of large ovate fossae separated by septum. Ovate posterior spermatheca behind each fossa. Sclerotized ducts present anterior to each spermatheca (Fig. 5D View Figure 5 ).

Variation.

Between paratype males and the holotype male, the coverings of white scales on the dorsal opisthosoma and carapace and the colular tuft are more or less distinct, likely due to scales rubbing off. The width and colour of orange tracts of scales marking the ocular quadrangle also slightly vary (Fig. 7A-D View Figure 7 ).

Dimensions.

Males. Total length: 4.10-4.25 (4.17 ± 0.06, n=4). Carapace length 2.02-2.35 (2.18 ± 0.12, n=4). Opisthosoma length 1.87-2.17 (1.99 ± 0.12, n=4).

Female. Total length: 5.12. Carapace length: 2.39. Opisthosoma length: 2.73.

Courtship display.

The male elevates a single leg III, slowly waving it in a partially flexed position (Fig. 6B, C View Figure 6 ). As the female approaches, the male raises and more rapidly waves both legs III (Fig. 6D View Figure 6 ). The opisthosoma is rapidly bobbed upwards and downwards but not completely elevated. The rapid opisthosomal bobbing created audible vibrations on the surface of the leaf shown in Fig. 6D View Figure 6 . Only partial courtship display observed in an artificial environment, in the wild males may exhibit a more complete courtship display with multiple modes of courtship.

Distribution and habitat.

Known only from 9.5 km SSE of Mount McIntyre, 9.4km SSE of Mount McIntyre, and 14.1km E of Nangwarry (Fig. 9 View Figure 9 ). Curiously, M. nemo was found in an ephemeral wetland complex on marshy vegetation in shallow water (Fig. 8 View Figure 8 ). No other species of Maratus are known to occupy such habitats.