Research Article |
Corresponding author: Cristina Anne Rheims ( carheims@gmail.com ) Academic editor: Jeremy Miller
© 2018 Cristina Anne Rheims, Giraldo Alayón.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Rheims CA, Alayón G (2018) A new genus of minute Sparianthinae spiders from the Caribbean (Araneae, Sparassidae). ZooKeys 742: 13-22. https://doi.org/10.3897/zookeys.742.21819
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The monotypic genus Diminutella gen. n. is proposed to include the type species, Diminutella cortina sp. n., described from San Diego de los Baños, based on male and female specimens. This species is amongst the smallest Sparianthinae known to date reaching only 4.4 mm body length. It can be distinguished from other Sparianthinae by the combination of eye arrangement, with anterior eye row recurved, posterior eye row straight, spination pattern of legs I–II, with three ventral pairs on tibiae and one on metatarsi, and by the peculiar genitalia, with male palps bearing a large, laminar, layered conductor that rests within a retrolateral depression in the cymbium, and a female vulva with long copulatory ducts coiled around the stalk of a globose blind ending appendage.
Cuba, Diminutella gen. n., taxonomy, West Indies
Sparianthinae Simon, 1897 is a well-established subfamily of Sparassidae Bertkau, 1872, characterized by the presence of a trilobate membrane with small or inconspicuous median lobe on metatarsi I–IV, small retromarginal denticles on the chelicerae and a median apophysis on the male palps (
The subfamily occurs worldwide, but the Neotropical region is particularly rich in terms of Sparianthinae fauna and recent papers (
In this paper, we describe the new genus Diminutella gen. n. to include a species of minute Sparianthinae, Diminutella cortina sp. n., found in San Diego de los Baños, western Cuba. It is one of the smallest species of Sparianthinae known to date, with total body lengths ranging from 3.5 to 4.4 mm. Amongst Neotropical Sparianthinae, similar sizes are only found in the genus Uaiuara, with total lengths ranging from 3.7–10.0 mm (
In the absence of a cladistic analysis, not much can be said about the relationships between Diminutella gen. n. and the remaining Sparianthinae genera. However, despite being known from a single species, we consider that the genus represents a monophyletic unit. Diminutella gen. n. shows a combination of somatic characters that is not found in any other genera of Neotropical Sparianthinae and both male and female genitalia are markedly different from all other species known to date. The importance of spines, male palp and female epigyne features was previously pointed out by Rheims & Alayón (2016). Also, Sparassidae species are usually conservative and rarely deviate from the generic bauplan. We consider that, if new species of Diminutella gen. n. are discovered in the future they will show the same characters that are currently used to diagnose the genus and will strengthen our hypothesis that this is a separate lineage within Sparianthinae.
The examined material is deposited in the collections of the Museo Nacional de Historia Natural de Cuba, La Habana, Cuba (MNHNCu, curator: G. Alayon) and National Museum of Natural History, Smithsonian Institution, Smithsonian Institution, Washington D.C., USA (
Morphological observations and illustrations were made using a Leica MZ165C stereomicroscope with a camera lucida. Measurements were taken with a micrometric ocular and are given in millimeters. Female genitalia were examined in clove oil after dissection. Photos of dorsal habitus, male palps, and female epigyne were taken using a Leica DMC 4500 camera attached to a Leica M205 A stereomicroscope. Extended focal range images were composed with the program Leica Application Suite version 4.8.0. SEM images were taken with a FEI Quanta 250 scanning electron microscope from the Laboratório de Biologia Celular at the Instituto Butantan. Material used for SEM was mounted on metal stubs and sputter coated with gold.
Abbreviations used throughout the text are given bellow.
Somatic morphology
AER anterior eye row
ALE anterior lateral eyes
ALS anterior lateral spinnerets
AME anterior median eyes
d dorsal
p prolateral
PER posterior eye row
PLE posterior lateral eyes
PLS posterior lateral spinnerets
PME posterior median eyes
PMS posterior median spinnerets
r retrolateral
v ventral
Male palp
dRTA dorsal branch of RTA
RTA retrolateral tibial apophysis
vRTA ventral branch of RTA
VTA ventral tibial apophysis
Format of descriptions follows
Diminutella cortina sp. n.
The specific name is a combination of the Brazilian adjective “diminuto” and the suffix “ella” and refers to the minute size of the specimens of the type species of the genus, considered the smallest Sparassidae known to date. Gender is feminine.
Species of Diminutella gen. n. can be distinguished from all known Neotropical genera by the combination of the following characters: AER recurved and PER straight (Figs
See species description.
Monotypic: Minutella cortina sp. n.
Pinar del Rio, Cuba.
Holotype ♂: CUBA, Pinar del Rio, San Diego de los Baños [22°38'N, 83°22'W], Hacienda Cortina, September 1985, G. Alayón leg. (
The specific name refers to the type locality of the species, Hacienda Cortina.
Diminutella cortina sp. n. is distinguished from those of the remaining Neotropical Sparianthinae genera by the male palp with large hyaline, layered, laminar conductor resting within retrolateral cymbial depression (Figs
Male (holotype). Prosoma orange with pale brown margins, thin dark brown line along lateral margins of cephalic region and fovea and faint brown reticulated pattern extending posteriorly from behind posterior eyes to thoracic region. Eye borders black (Fig.
Diminutella cortina sp. n. A–C male (holotype), left palp A prolateral B ventral C retrolateral D–F female (paratype) D epigyne, ventral E vulva, dorsal F schematic course of internal duct system. BP – blind ending appendage; C – conductor; CD – copulatory duct; dRTA – dorsal branch of RTA; E – embolus; FD – fertilization duct; LL – lateral lobe; MA – median apophysis; MS – median septum; SP – spermathecae; ST – subtegulum; T – tegulum; TBE – tegular projection at base of embolus; vRTA – ventral branch of RTA; VTA – ventral tibial apophysis. Scale lines: 0.5 mm.
Female (Paratype,
Males (n = 2): total length 4.2–4.4; prosoma length 2.0–2.1. Females (n = 4): total length 3.5–4.4; prosoma length 1.7–2.0; femur I length 1.4–1.6.
Known only from the type locality.
This study was supported by Fundação de Amparo à Pesquisa de São Paulo (FAPESP no. 18982-0). We wish to thank Beatriz Mauricio (Laboratório de Biologia Celular, Instituto Butantan, São Paulo) for helping with SEMs; Lauren Esposito (California Academy of Sciences, California, USA), Peter Jäger (Senckenberg Research Institute and Museum, Frankfurt am Main, Germany), Ingi Agnarsson (University of Vermont, Vermont, USA), Majid Moradmand (University of Isfahan, Isfahan, Iran) and Jeremy Miller (Naturalis Biodiversity Center, Leiden, Netherlands) for greatly improving the quality of this manuscript.