Dendryphantina

Edwards, G. B., Baert, L. & Fdacs, 1903, New Species, Combinations, and Records of Jumping Spiders in the Galápagos Islands (Araneae: Salticidae), Belgian Journal of Entomology 67, pp. 1-27 : 1-27

publication ID	https://doi.org/ 10.5281/zenodo.13271950
persistent identifier	https://treatment.plazi.org/id/F217A845-FFBD-FFEB-8D43-FC66FE6EFCE1
treatment provided by	Felipe
scientific name	Dendryphantina
status

Treatment

Subtribe Dendryphantina

Cerionesta pacifica ( Banks, 1902) View in CoL comb. nov.

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Figs 6-8 View Fig View Fig View Fig

Philaeus pacificus BANKS, 1902: 67 View in CoL (Description male & female).

RECORDS: Isla Pinzon , 5 km W of Playa Escondida central crater, 280 m, arid forest, 19.VI.1991, 1 male (J. Heraty, H91/101). Isla Santa Cruz, above Baranco at CDRS, 40 m, malaise trap, 1-30.VI.1991, 1 female (S. Peck) .

DIAGNOSIS: The enlarged, forward-projecting chelicerae of some (“major”) males with a robust retromarginal tooth on a prominent ventral bulge, and the shapes of various palpal structures (curled retrolateral embolus with expanded disk-like embolus base, peripheral tegular duct with a ventral origin, and long sinuate RTA), distinguish the male from any other Galapagoan species. There are other small ( “minor ”) males in which the cheliceral development is not obvious, but other characters, such as palpal structure, will distinguish them. Intermediate males have the chelicerae slightly diverging (as if they only have the basal part of the chelicerae that occurs in major males, in which the distal ends of the chelicerae converge and become parallel).

The palpal femur has a dorsal row of macrosetae exceeding three in number (usually four), which is also true of Messua avicennia sp. nov. (usually eight), although the palpal macrosetae of C. pacifica are somewhat more elongate than in M. avicennia . This is unusual in salticids, which normally have an x-x-x pattern of macrosetae on the appendage segments (see RAMÍREZ, 2014).

14 Like the male palpal structures, the female epigynal structures (posterior spermathecae, sinuate copulatory openings, medial copulatory ducts bent outward with the rims extending at an acute angle from the copulatory openings) are distinctive. This is similar to the typical dendryphantine epigynal structure that was described by MADDISON (1996), but the details are consistent with Cerionesta ( Peckham & Peckham, 1893) . Also see Messua avicennia diagnosis.

NOTES: Philaeus Thorell, 1869 , is an Old World genus belonging to the large clade Saltafresia, which is not closely related to the Dendryphantini (part of the larger clade Marpissoida) to which this species belongs ( MADDISON, 2015).

According to RUIZ (2010; pers. comm. 2016), this species either belongs in Cerionesta or a related undescribed genus, due to its embolus shape and position, and apparently in having the tegulum basal division turned 90 degrees clockwise. Rather than describe another monotypic genus, we place it in the previously monotypic genus Cerionesta , as it seems to be related to the type species, C. luteola Peckham & Peckham, 1893 .

The ventral projection of the chelicerae can also be seen in some species of the unrelated genus Myrmarachne Macleay, 1839 (e.g., YAMASAKI & AHMAD, 2013), and may be an adaptation to strengthen elongated male chelicerae. Other possibilities are that along with allometric size advantage (see FABER, 1984) this modification serves as additional armature for male-male encounters, or perhaps is involved in subduing a specific prey type that males prefer due to their otherwise unwieldy elongate chelicerae (see JACKSON & WILLEY, 1994).

Messua avicennia sp. nov.

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Figs 9-10 View Fig View Fig

ETYMOLOGY: A noun in apposition after the genus name of the dominant plant in a habitat where this species occurs.

TYPES: Holotype male from Isla Floreana : 1991, coll. L. Baert, K. Desender, J.P. Maelfait, I.G.: 27.720 (B.91/633); female paratype, same data as male; female paratype, Isla Floreana , Punta Cormorant , 22.II.1988, coll. L. Baert, K. Desender, J.P. Maelfait, I.G.: 27.318 (B.88/334); male paratype, Isla Santa Cruz , Charles Darwin Research Station, elevation 0-1 m, mangrove litter, 12.II.1982, coll. L. Baert (B.82/010). One male and five female paratypes, Isla Rábida, elevation 3-10 m, sweep Avicennia , margin of lagoon, dry sand, 28.IX.1975, coll. W.G. Reeder ( TMM #57506 View Materials ).

DIAGNOSIS: Males are easily distinguished from other Galapagoan salticids by the strongly divergent, forward projecting chelicerae. They may be distinguished from Cerionesta pacifica in that the chelicerae of major males of the latter species are distally parallel rather than divergent, and the palpal structure is much different, with the embolus originating dorsally in M. avicennia , but retrolaterally in C. pacifica . As in other species of the limbata species group ( RUIZ, 2010), there is a long row of macrosetae on the dorsum of the palpal femora (usually eight). Females have a typical curved ‘X’ form ( RUIZ, 2010) to the structure of the epigyne, similar to C. pacifica , but the ducts of M. avicennia are not advanced as far anteriorly nor are the atrial rims as acutely bent laterally as in that species. In addition, M. avicennia has a more robust body shape than C. pacifica .

Males are distinguished from other Messua species by having the embolus more elongate, directed more ventrally, and the embolus base is hidden on the dorsal side of the bulb. It is expected that female epigynal copulatory ducts would match the embolus and be longer than in related species, but the genus needs to be revised to confirm this correlation.

16 DESCRIPTION: Male holotype (paratypes in parentheses): BL 4.85 (3.99-4.11), CL 2.38 (1.95- 2.22), CW 2.16 (1.67-1.88), AER 1.51, PER 1.78. Carapace, sternum, palps, and all leg femora dark brown, most of remainder of spider medium brown, except all metatarsi distally darker, and all tarsi yellow. Faint indications of dorsal pattern similar to some females may exist on the abdomen, and abdominal venter yellowish cream with brown median stripe as in female. Leg macrosetae: I M v 2-2, Tb v 2-2-2(r offset proximally), P p 1, F dp 2-0-0; II M p 0-1, v 2-2, Tb p 0-1-0, v 2-1r-1r, P p 1, F dp 2-0-0, dr 1-0-0; III M p 2-1, v 2-0, r 2-1, Tb p 0- 1-1, v 2-0-0, r 0-1-1, P p 1, r-1, F dp 2-0-0, dr 1-0-0; IV M p 2-1, v 2-0, r 2-0, Tb p 0-0-1, v 2- 0-1p, r 0-1-1, P p 1, F dp 1-0-0.

17 Female alloparatype (second female paratype in parentheses): BL 3.72 (3.55), CL 1.78 (1.67), CW 1.53 (1.42), AER 1.26, PER 1.44. Similar to male overall, but cephalothorax and appendages more or less medium brown, not as dark as male. Dorsal abdomen with variable pattern, sometimes with three sets of yellowish spots in posterior half, first two pair transversely linear in shape (all of which may be reduced or absent). Leg macrosetae similar to male.

NOTES: This was the undetermined dendryphantine reported by GALIANO & BAERT (1990). It apparently is mostly a coastal species, and commonly has been taken sweeping mangrove ( Avicennia sp.) and from mangrove litter. However, it has also been reported in other habitats up to 700m ( GALIANO & BAERT, 1990).

Comparison of specimens from Hawaii, Arizona, and Texas that are identified as Messua felix (F. O. Pickard-Cambridge, 1901) or M. cf. felix show the embolus of males of these specimens to be a distal concave curved shape more typical for this group of Messua , unlike the dorsally-extended embolus of M. avicennia . Although M. felix (or a closely related species) is thought to be introduced to Hawaii, it is not the species that occurs in the Galápagos Islands, which supports the hypothesis that M. avicennia is an endemic Galapagoan species.