JOURNAL OF CRUSTACEANBIOLOGY, 25(4): 547-550, 2005 FIRST RECORDS OF THE FAIRY SHRIMPSTREPTOCEPHALUS MOOREI (BRANCHIOPODA:ANOSTRACA) FROM THE UNITED STATES AlejandroM. Maeda-Martinez,D. ChristopherRogers, and Richard D. Worthington (AMMM, correspondence)Centro de InvestigacionesBiol6gicas del Noroeste, S. C., Apartadopostal 128, La Paz, Baja CaliforniaSur, 23000, Mdxico ([email protected]); (DCR) EcoAnalysts, Inc., 166 Buckeye Street, Woodland, California95695, U.S.A. (RDW) University of Texas, El Paso, P.O. Box 13331, El Paso, Texas 79913, U.S.A. ABSTRACT We reportthe firsttwo recordsof the fairyshrimp Streptocephalus moorei from the UnitedStates, previously known only from its type localityin southeasternChihuahua, M6xico. An updatedmorphological diagnosis and habitat data are provided. Streptocephalus moorei, previouslyconsidered as a criticallyendangered species under the IUCN red list criteria,is now assessedas an endangeredspecies on the basisof the followingcriteria: area of occupancyestimated to be less than500 km2,known to existat no morethan five locations,and extremefluctuations in thenumber of matureindividuals. Appropriate measures should be takento protectthis species, such as additional surveyefforts and monitoring of extantpopulations. Almost 25% of the anostracanspecies are known only from assessmentfor this species was made using the IUCN red list categoriesand their type localities (Belk and Brtek, 1995, 1997). In the criteria(2001). genus Streptocephalus Baird, 1852, of the 13 species recognized from the New World, S. antillensis Mattox, RESULTS 1950, S. kargesi Spicer, 1985, S. moorei Belk, 1973, and Streptocephalusmoorei Belk, 1973 S. potosinensis Maeda-Martinezet al., 1995a, have been Fig. 1 from a reportedonly single location (Maeda-Martinezet al., Streptocephalusmoorei Belk, 1973.-Brtek, 1974; Belk, 1975; Spicer, 1995a), and S. guzmani Maeda-Martinezet al., 1995a, S. 1985; Maeda-Martinez,1991; Maeda-Martinezet al., 1995a, b, 2002. mattoxi Maeda-Martinez et al., 1995a, and S. wootoni Eng, Type Material.-Holotype and paratypesat National Museum of Natural Belk, and Eriksen, 1990, have been considered geograph- History, U.S.A. (USNM 141454, 141455), paratypes at Muzeum v ically restricted species (Eng et al., 1990; Brown et al., Bonjniciach,Bojnice, Czechoslovakia(VII/a-2510), and at Loyola 1993; Maeda-Martinezet al., 1995a). The last three species University Museum, New Orleans,Louisiana, U.S.A. (LU-1341). The type and S. moorei were listed in the 1996 IUCN red list of materialwas collected on 30 August 1971 by J. J. Landye (Belk, 1973). threatened animals. woottoni is the Streptocephalus only TypeLocality.--Federal highway 45, 10 miles N of Jim6nez, includedin the list of the streptocephalid endangeredspecies Chihuahua,M6xico, 27020'N, 104'55'W (Belk, 1973). United States by the U.S. Fish and Wildlife Service and thus is the only member of the family receiving legal protection New Localities.--(1) Stock tank on south side of road, dug (FederalRegister, 1993). into playa, 13.5 road miles (21.7 road km) E of Columbus During studies on two ephemeralpools in southernNew (T29S, R6W, ctr. Sec.12), Luna County, New Mexico, Mexico, U.S.A., in 1995, 1999, and 2000, two of us (DCR U.S.A., 31047.98'N, 107024.55'W(GPS). (2) Stock tank,dug and RDW) collected specimens of Streptocephalusmoorei, into Cedar Lake Playa, ArmenderasRanch, Sierra County, a species previously known only from the state of New Mexico, U.S.A., 33013'41.29"N, 107001'33.50"W Chihuahua,Mdxico. These new recordsrepresent a consider- (GPS). able extension of the distribution range of the species. The Material Examined.-From type locality: ParatypesDB 062, 2 males, 14.4, objective of this paperis to formallyreport this species from 15.0 mm, 2 females, 12.0, 12.2 mm, collected 30 August 1971 by J. J. the United States and to updatethe morphologicaldiagnosis, Landye. From Columbus: DCR-183, 6 males, 5.4-7.2 mm, collected 12 habitatdata, and conservationstatus of the species. October 1995 by R. Worthington;DCR-192, 1 female, 8.2 mm, collected 26 September1999 by R. Worthington;and DCR-194, 24 males, 16.0-18.6 mm, CIB-450, 3 males, 16.7-18.6 mm, collected 13 October 1999 by R. MATERIALSAND METHODS Worthington.From Armenderas Ranch: DCR-236, 8 males, 16.7-18.6 mm, The materialexamined is depositedin the collectionsof Centrode collected 17 September2000 by D. C. Rogers and B. Lang. All the material InvestigacionesBiol6gicas del Noroeste,S. C. (CIB), La Paz, Baja from the new localities was identifiedby D. C. Rogers. CaliforniaSur, M6xico, and the privatecollections of D. Christopher Rogers(DCR), and Denton Belk (DB) (currentlydeposited at the National Diagnosis.-Male (abbreviationsrefer to labels in Fig. 1): Museumof NaturalHistory, Smithsonian Institution, Washington, D. C., peduncle (pd) of distal outgrowth of long type, without U.S.A.). first geniculation of medial, Standard pulvinus; peduncle bearing length values (measuredfrom the anteriormargin of the head directed, inner to the posterior of the telson between the are for ventrally large digitiformprotuberance (dp); margin cercopods) given surface of distal of with 4 to 10 the specimens examined. Measurementswere made using a verniercaliper portion peduncle small under a stereoscopic microscope. Terminology used in the morphological conical protuberances,variable in size; lateral surface of diagnosis follows Maeda-Martinezet al. (1995a, b). The extinction risk distal part of peduncle, near base of hand bearing 6 to 12 547 This content downloaded from 200.23.161.198 on Mon, 17 Feb 2014 18:31:06 PM All use subject to JSTOR Terms and Conditions 548 JOURNAL OF CRUSTACEAN BIOLOGY, VOL. 25, NO. 4, 2005 distal part of thumb and spur; inner lamella medioventrally produced, forming cavity; thumb elongate, proximal two- thirds slightly curved upward, last third strongly curved; n- ce apex of thumb acuminate; dorsal margin with series of unequal peg-like spines; finger (fi) bigeniculate,inner dorsal side of proximal part, with single, anteromediallydirected, hump-like tooth; apex of finger acuminate,with subapical, 1 ventrolaterallydirected, digitiform structure;distal segment of second antennawith apex fleshy; frontalappendage short; fa genitalia without linguiform outgrowths; cercopods sepa- rate, setose along inner and lateralborders; anus terminal. Female. Ovaries biramous, variably extending from thoracic to abdominal 6-8; - 4- aj segments 9-1.1 segments cysts pd spherical, ornamentedby ribs forming polygonal areas. - Remarks.--On the diagnosis of the species based on the type cp material, Maeda-Martinez et al. (1995a) wrote "frontal appendageshort, distal part with a pair of conical protuber- ances, in ventrolateralposition." After a reexaminationof VP-. males of the type material,the frontalappendage appears short and finishes slightly bilobed. The frontalappendage in males . .-.. of the new materialis relatively longer and is subacuminate (Fig. 1). Here the ventrolateralconical protuberancesare on the middle partand not on the distal part.This differencemay be a size-dependantvariation, given that the males collected from New Mexico are than those of the material. :? larger type ? An additionalfeature of the male S. moorei not mentioned before is the fleshy consistency of the apex of the distal sp.. segment of the second antenna,which is typically chitinous in most Streptocephalus species. Differential Diagnosis.--Streptocephalus moorei exhibits the most complex distal antennaloutgrowth of all American species, and bears a number of similarities with S. antillensis. The unique features of S. moorei are (1) the large digitiform protuberanceon the inner side at the first geniculation of the peduncle, (2) the series of 8 to 12 vermiformprotuberances on the lateralside of the distal part of the peduncle, and (3) the long, curved process on the dorsolateralside of the base of the thumb (Maeda-Martinez '- th et al., 1995a) (Fig. 1). Species Group.-Streptocephalus moorei is considered as part of the torvicornis group, mackini subgroup. The torvicornis group is distributed in Africa, the Arabian peninsula, Europe, and North America; the mackini sub- group is distributedonly in North America. The diagnostic characteristicsof the mackinisubgroup are male with frontal appendage simple and short; peduncle of distal outgrowth Fig. 1. Anterior view of head and right antenna of male of Streptoce- phalus moorei Belk, 1973 (specimen from Columbus, Luna County, New long, without pulvinus; spur of thumb well developed; Mexico, U.S.A.). aj, apical joint; an, antennule;bj, basal joint; ce, genitalia without linguiform outgrowths;cercopods setose; compound eye; cp, conical protuberance;fa, frontal appendage;fi, finger; female with biramous ovaries (Maeda-Martinez et al., lp, curved process from base of thumb;pd, peduncle; sp, spur; th, thumb; 1995b). and vp, lateralvermiform protuberances of peduncle. Scale bar = 1.0 mm. Distribution and Ecology.--Type locality (Fig. 2): The ecology of Streptocephalus moorei at the type locality is vermiform protuberances(vp); dorsolateralsurface of base poorly known. Specimens of the species have been collected of thumb (th) with long, anterodorsallydirected, subacumi- only once at this location. In August 1971, S. moorei was nate process that curves ventrallyapically; spur (sp) broadat collected along with S. mackini Moore, 1966, Thamnoce- base, narrow at middle; spur bearing subapical rounded phalus platyurus Packard, 1879, Triops sp., Eocyzicus dorsal protuberance;apex of spur