Mangrovia, Framenau & Castanheira, 2022

Framenau, Volker W. & Castanheira, Pedro de S., 2022, A new genus of Australian orb-weaving spider with extreme sexual size dimorphism (Araneae, Araneidae), Zoosystematics and Evolution 98 (1), pp. 137-149 : 137

publication ID	https://dx.doi.org/10.3897/zse.98.82649
publication LSID	lsid:zoobank.org:pub:E428377B-5186-45AE-A97F-A82D4F5C5BD4
persistent identifier	https://treatment.plazi.org/id/AFC772CC-2A82-4533-BF66-0317BAACE2AD
taxon LSID	lsid:zoobank.org:act:AFC772CC-2A82-4533-BF66-0317BAACE2AD
treatment provided by	Zoosystematics and Evolution by Pensoft
scientific name	Mangrovia
status	gen. nov.

Treatment

Mangrovia gen. nov.

Type-species.

Epeira albida L. Koch, 1871, designated here.

Etymology.

The genus-group name is derived from the general habitat preferences of the two species, which are often found in coastal mangroves and woodlands. The gender is feminine.

Diagnosis.

Within an Australian context, Mangrovia gen. nov. males have only a single patellar spine on the pedipalp, a character considered a putative synapomorphy of the backobourkiines. However, Mangrovia gen nov. differ considerably from members of the backobourkiines by somatic and genital morphology. Both species in the genus display eSSD with females about 3-5 times larger than males, but eSSD is absent in the backobourkiines (with the exception of B. collina and species in the Backobourkia dehaani -group (sensu Yin et al. 1997)). The median apophysis in backobourkiines is elongate transverse with the base forming an arch over the radix, but it is short with an apical, spine-like projection in Mangrovia gen. nov. The female epigyne in Mangrovia gen. nov. has a terminal pocket, absent in all backobourkiines.

Mangrovia gen. nov. differs from the members of the zealaraneines as currently known (see Introduction section) by its eSSD, absent in any known zealaraneines, and the presence of only one patellar spine on the male pedipalp, whereas there are always two in zealaraneines ( Court and Forster 1988). The median apophysis of zealaraneines is elongate transverse, with a variable number of spine-like protrusions, but much shorter and only with a single spine-like protrusion in Mangrovia gen. nov.

Outside the backobourkiines and zealaraneines, Mangrovia gen. nov. appears most similar to species of Neoscona ( Berman and Levi 1971; Grasshoff 1986; Levi 1993a), in particular with respect to the male genitalia. However, eSSD is absent in any known Neoscona species and males of Neoscona have distinctly enlarged tibiae on the second leg with numerous and strong spines, often in diagnostic arrangement. Mangrovia gen. nov. males do not have enlarged tibiae II. In contrast to Mangrovia gen. nov., males in Neoscona have two patellar spines on the pedipalp, not one, and the embolus of Mangrovia gen. nov. has a subterminal side branch (e.g. Fig. 2B, C View Figure 2 ), not present in Neoscona . An embolus lamella is absent in Mangrovia gen. nov. males, but present in Neoscona (e.g. Levi 1993a; fig. 6).

Description.

Small to medium-sized orb-weaving spiders with eSSD (TL males ca. 2.5-3 mm, females ca. 8-10 mm). Carapace (Figs 1A View Figure 1 , 3A View Figure 3 , 6A View Figure 6 , 8A View Figure 8 ) rounded pear-shaped, longer than wide; colouration variable from light brown to reddish-brown with dusky edges on males. Eyes: AME largest, row of PE slightly recurved, lateral eyes almost touching, PLE separated from PME by approximately their diameter in males and by more than their diameter in females. Chelicerae paturon and fangs yellowish- to reddish-brown. Females with four promarginal teeth and three retromarginal teeth, males with three promarginal teeth and two retromarginal teeth. Labium wider than long, subtriangular, with front end bulging and white. Endites elongate-rounded, beige to light brown with antero-mesal corner shiny and white. Sternum heart-shaped, slightly longer than wide, with dark edges (Figs 1B View Figure 1 , 3B View Figure 3 , 6B View Figure 6 , 8B View Figure 8 ). Legs: leg formula I > II > IV > III (males) or I > IV > II > III (females). Abdomen about as long as wide, dorsum with dark folium pattern in males, varying from uniformly grey to beige with anterior black area on females; venter black with a pair of white guanine spots. Genitalia: male pedipalp patella with a single strong spine (e.g. Fig. 1C, D View Figure 1 ); paracymbium poorly developed (Figs 1D View Figure 1 , 2C View Figure 2 ); radix elongate (Figs 2B View Figure 2 , 7A View Figure 7 ); no obvious stipes, possibly fused with radix (see Discussion); median apophysis oval, bearing a heavily sclerotized and acute apical process (Figs 1C View Figure 1 , 2A View Figure 2 , 6C View Figure 6 ); conductor conspicuous, robust, basally sclerotised but apically fleshy (Figs 1C View Figure 1 , 2C View Figure 2 , 6A View Figure 6 ); terminal apophysis well-developed, somewhat spoon-shaped, not sclerotised (Figs 2A, B View Figure 2 , 7A, B View Figure 7 ); subterminal apophysis elongate and thin (Figs 1D View Figure 1 , 2A, C View Figure 2 , 6D View Figure 6 ); embolus heavily sclerotized, basally inflated, then straight, thin and elongated, with subterminal short branch (Figs 2B, C View Figure 2 , 4C, D View Figure 4 , 7A View Figure 7 ). Epigyne base plate wider than long; scape elongate and reaching posteriorly beyond the base plate and bearing a terminal pocket; atrium rounded and very conspicuous, located almost on the border of genital area (Figs 3C-E View Figure 3 , 8C-E View Figure 8 ); spermathecae ovoid, separated by less than their diameter; fertilisation duct basally convoluted and attaching posteriorly to spermathecae (Fig. 4A, B View Figure 4 ).