After the insects, spiders (belonging to the arachnid order Araneae) are probably the most varied group of animals on the island. I would guess that the number of species is in the dozens, but to my knowledge, a formal survey of spider diversity on the island has not yet been done.
The spiders of St. Martin have a wide diversity of hunting techniques and seem to occupy almost every type of habitat on the island, from scrubland to dense forest to human habitations.
The most visible species are included here in some detail, while other species are included with photographs and identification where available. Future field research on St. Martin has been planned and will hopefully shed additional light on the spider diversity of the island.
Silver Argiope (Argiope argentata) and Banded Garden Spider (Argiope trifasciata)
The silver argiope is very common on St. Martin. In scrubland areas, it can be almost impossible to walk between any two nearby bushes without walking through one of their webs. The upperside of this spider is silvery white in front and dark with white markings in back. The underside is dark with yellow markings, and the legs are typically banded in black, yellow and orange.
An orb-weaving spider of the family Araneidae, it weaves large webs, sometimes reinforcing the center with an x-shaped group of zig-zagging lines. Young individuals may weave webs in grass with irregular reinforcement in the center. I have also seen smaller individuals in webs created at the edge of larger webs.
When approached, they typically run towards one of the anchor points of their web. The females can be quite large, over three centimeters in body-length, while the males don’t exceed two centimeters. The bite of this spider is reported as being painful and itchy for an hour or so, but despite walking through hundreds of webs I have not yet been bitten.
The banded garden spider is a closely related species, similar in most respects, but the top of its abdomen is banded. It is widely distributed around the world, but much less common on St. Martin than the silver argiope.
Spiny-backed Orbweaver (Gasteracantha cancriformis)
This spider, also referred to as the crab spider and many other combinations of crab, spiny and orbweaver, is quite common on the island and inhabits both scrubland and forested areas. It is also quite variable in color and markings.
This spider is typically identified by the presence of six spines on the abdomen, but on St. Martin typically only four are visible. There are a variety of different color variations, the most common being red-orange and yellow and black and white. In North America, which makes up the bulk of its range, there are also a variety of color variations, but typically all six spines are visible.
Although its webs are quite large, the spider itself is small, less than a centimeter in length. These spiders typically live only shortly after reproducing. Males of this species are much smaller than females. One may easily identify their webs because the outer support lines are reinforced at regular intervals, giving the appearance of a dotted line along the perimeter of the web.
Gray Wall Jumper (Menemerus bivittatus) and Pantropical Wall Jumper (Plexippus paykulli)
These jumping spiders, particularly the gray wall jumper, are exceedingly common around human habitation, and I typically have at least a dozen in and around my apartment at any given time. These spiders do not spin webs, but feed by attacking their prey on foot. In most cases, they are not particularly bothered by human presence, and this is particularly true when they are devouring a fresh kill.
The admittedly incomplete selection of spiders on the following pages is meant to serve as a starting point for understanding the tremendous variety and great beauty of these creatures.
It may be worth noting that many totally unrelated spiders are referred to as crab spiders because they either look or walk like crabs. Conversely, various crabs are referred to as spider crabs. There is no taxonomic significance to these common names.