Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes


Clam shrimp, live - Eulimnadia geayi - female

Clam shrimp, live - Eulimnadia geayi - Female
Kirtland AFB, Bernalillo County, New Mexico, USA
July 31, 2013
Size: 7 mm Carapace
Download high resolution image here.

This is the main discussion page for 5 sets of images of specimens (one set per specimen) of what I've identified as Eulimnadia geayi. All specimens were collected from a vernal pool at 35°03'01.1"N 106°36'16.6"W at 5249 ft. elevation near the southern end of Carlisle Blvd., (Albuquerque East 7.5 minute quadrangle), Kirtland AFB, Bernalillo Co. NM. All key and other described features needed to identify the species are visible in one or more of the posted images. Expert confirmation is appreciated. This species has heretofore apparently only been reported from Venezuela, Colombia, Mexico(1), and Brasil(2). Rabet 2010(3), however, states, "the occurrence of this species in Colombia is not established". This is due to confusion with a Venezuelan locality. It also states, "Localities in Mexico (Daday de Deés 1926) should be confirmed by genetic or egg morphology studies". Regarding the latter, Belk 1989(4) concludes that adult morphology is generally inadequate for species ID in this genus, and that use of egg features is required.

The pool is primarily supplied with water from an adjacent parking lot. However, spillover from the KAFB/Albuquerque International Airport runway apron (across the street) may contribute during heavy rains. During the rainy season (mid summer to mid fall), the pool sometimes contains water for a long enough period of time (weeks) to complete a clam shrimp generation. Their eggs can remain dormant for several years in dry soil in the meantime.

Genus ID is based on the key of Rogers, et al., 2012(5). The following key features link to the image page that best displays them: Frontal organ pedunculate; Telson posterior margin spine rows with dorsal confluence not produced; carapace not carinate; Telson with a ventral spiniform projection just anteriad of cercopod base; Cercopods arcuate and slightly longer than telson ventral margin; Carapace smooth between growth lines.

Species ID is based on egg features from the key of Rabet 2010(3): eggs cylindrical with one end inflated; one end domed; One end slightly wider than the other; dome end moderately inflated, ridges narrow. Indeed, our egg side, bottom, and top views (by our convention) match fairly well Rabet 2010(3) Figs. 3A, B, and C, respectively. The two perspectives shown in Martin 1989(6) Fig. 4D also compare favorably, and serve to show the degree of variability in detail.

Although insufficient as the basis for ID on its own, species ID is corroborated by adult features being consistent with the description and drawings of E. geayi in Pereira 2001(1). The gylcerin saturated female has carapace length 8.4 mm, height 5.3 mm, and shape consistent with Fig. 2B. From this specimen's telson image we see 2 rows of 14 sharp spines, where the terminal spine is larger and wider than preceding ones. The ventral margin of the telson has a well-developed blunt spine. Setae, filaments, and spinules are wetted down or otherwise obscured by glycerin for this specimen. From the desiccated adult telson, though, we see "Caudal furca with plumose setae and small spinules on distal end" and "Telson filaments arising at level of second or third posterior spines". Also, the male carapace has length 6.6 mm, height 4.3 mm, a shape consistent with Fig. 2A, and a "minutely granulate ventral margin".

Follow-up 28 OCT 2016. I emailed D. Christopher Rogers about my find. He replied, "Wow: it does bear a strong similarity to E. geayi. Any chance you could send me specimens so I can run the DNA? At the very least, if you could send me a gallon ziplock bag of soil (only from the top 2 cm of the substrate) from that pool so that I can start a culture, and can examine more eggs and adults, it would be greatly appreciated." I've sent the requested samples, and will report back his finding when I hear back from him.

Follow-up 16 NOV 2016. Dr. Rogers reports, "Well, I reared some of the Eulimnadia and looked at the material that Ed sent, and I must concur with Ed: it is Eulimnadia geayi ... Daday (1926) had one female [reported] from Coahuila. Martin (1989) and Maeda-Martinez et al. (2002) report that the specimen was badly damaged and not properly identifiable. Maeda-Martinez et al. (2002) state that they have not found any material in Mexico that matches E. geayi." Given these, and my prior comments regarding Rabet 2010(3) and Belk 1989(4), Dr. Rogers agrees that this post is the first valid record for North America.

Specimen image sets:

Thorough as always!
I can't comment on the ID, but I just have to say this is a excellent addition to a smaller corner of the guide.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.