Family Salticidae - Jumping Spiders

Maddison’s 2015 Phylogenetic Classification - An Overview

Historically, jumping spiders have been classified in a Linnaean hierarchical structure on the basis of morphological characters. In the early 1900s, Eugène Simon adopted this methodology using cheliceral dentition and body shape; subsequently in the 1970s, Prószyński’s applied genitalic characteristics to a Linnaean structure. While Simon’s schema was hampered by the fact that many groups of unrelated jumping spiders have similar body shapes, convergent evolution has limited Prószyński’s approach as different species may also have similar genitalic characters.

By the turn of the century, molecular phylogenetics was being applied to salticid classification. Molecular analysis is used to test various kinship hypotheses; the resulting data suggest/confirm groups that best fit the assumptions of cladistics.* This methodology in combination with descriptive and interpretive taxonomy, as well as accessible and comprehensive online libraries and catalogs, has resulted in the most recent advances in salticid classification. It is worth repeating that this new schema is a synthesis based on field records, traditional laboratory taxonomy, and molecular analysis. As Maddison makes clear, “The groups discovered by molecular data have coherence in general body form, in genitalia, and in geographical distribution.”

Maddison’s 2015 publication draws on these efforts to construct the outlines, if not all the details, of a ground breaking structure for a phylogenetic classification of salticids. With a focus on groupings above genera, his classification defines salticid subfamilies, tribes, and subtribes within larger clades.

*Briefly, cladistics uses shared derived characteristics (synapomorphies) to define a clade = an ancestor and all its descendants. Thus, a classification system employing cladistic analysis tells us something about the evolutionary history of the organisms involved.

Two examples elucidate the usefulness of cladistic analysis.

. . . it was long said that the orb-weaving spiders, with their intricate and orderly webs, had evolved from spiders with cobweb-like webs. The cladistic analysis of these spiders showed that, in fact, orb-weaving was the primitive state, and that cobweb-weaving had evolved from spiders with more orderly webs. (http://www.ucmp.berkeley.edu/clad/clad5.html)

Another example of the fruits of this methodology add insights into the worldwide distribution of jumping spiders. Biogeographers have long noted that closely related species are generally found in discrete areas - e.g. each continental land mass has a characteristic jumping spider fauna. Salticid clades defined by molecular analysis reflect this same general pattern of distribution.** This, in turn, supports the hypothesis that salticid evolution and radiation occurred after the breakup of Pangaea. See Hill and Edwards, 2013 for interesting details of the origins and distribution of North American jumping spiders.

**Exceptions to the rule do occur and lead to additional hypotheses regarding distribution (e.g. Habronattus spiders are part of an Old World group).

Maddison, Wayne. 2015. A phylogenetic classification of jumping spiders (Araneae: Salticidae). Journal of Arachnology 43: 231-292.

The largest family of spiders, with >315 species in 63 genera in our region(1) and >5,000 species described worldwide.

Anterior median eyes (the pair of eyes in the center front) are comparatively very large and give these spiders excellent color vision and high degree of resolution. The shape of the retinae appears to give the spider telephoto vision (2). See diagram of a typical arrangement of eyes in this family:

Worldwide

Overview of our fauna:

Family SALTICIDAE

sylvanus

pixii reticulatus

militaris rufa

palmarum

tillandsiae

harfordi watonus

pulcherrimus workmani

tux

tyrrellii

whitmani

mystaceus

pius regius

purpuratus texanus

putnami richmani

similis undescribed sp.

sexpunctatus

poultoni undescribed sp.

pikei robusta

taeniola

venator

scenicus

mataxus peckhami

sansoni tarsalis

formosus forticulus arcalorus

virgulatus

trimaculatus viridipes

altanus luminosus

Some Fruit Flies mimic salticids

(3)(4)