Halocoryza Alluaud 1919, sea-side beetles of the Indian, Atlantic (sensu lato), and Pacific Oceans: a generic synopsis and description of a remarkable new species from Baja California Sur, México (Coleoptera, Carabidae, Scaritini, Clivinina)

Abstract Information on the three previously described species of Halocoryza Alluaud is updated and a new species for the genus from Isla Carmen, Sea of Cortés, Baja California Sur, México is described. Halocoryza whiteheadiana sp. n. was found at UV light on a beach of that island. This species does not fit the profile of the other three species, i.e., living on coralline beach sands, or in the Mangrove intertidal zone. Two alternative possibilities as to why this is so are suggested and a study plan for testing these possibilities is proposed.


Introduction
Halocoryza beetles belong to the subtribe Clivinina and are closely related to the genus Schizogenius Putzeys 1846, the so-called Rib-headed Beetles that D.R. Whitehead revised for his doctoral dissertation and treated in subsequent publications (Whitehead 1966(Whitehead , 1969(Whitehead , 1972Whitehead and Reichardt 1977). During a review of collections for Volume 3 of my series of books on the Western Hemisphere Caraboidea (Erwin 2007;Erwin and Pearson, 2008), I discovered in the National Museum of Natural History collection a remarkable new species of Halocoryza from Isla Carmen in the Sea of Cortés, Baja California Sur, México.
It is named here in honor of Donald R. Whitehead † who had a great interest in this group of beetles and discovered a lot about their special place on the sea shore. I have personally collected but one specimen of this genus on the shore of the Caribbean side of Panamá, and was amazed that these beetles accept such saline conditions, as they do. Whitehead pondered whether Halocoryza should be included within Schizogenius, perhaps as a subgenus, as is Listropus Putzeys, a group that Whitehead and Reichardt (1977) ranked as such. Unfortunately, Whitehead was not able to continue with this study due to his early death. Here, I am retaining the generic status he left in legacy because I believe ecological shift, in addition to structural and physiological attributes, should be an important element in deciding classification status. A shift to salt from fresh water is one that must be difficult. Living in a very saline habitat requires markedly specialized characteristics, both physically and physiologically (Kavanaugh and Erwin 1991). When additional specimens become available, especially males, classification of this species needs to be revisited.

Methods and specimens
Methods and species concepts follow those previously described (Erwin and Kavanaugh 1981;Kavanaugh and Erwin 1991). The species validation and diagnosis format follows as closely as possible that suggested in Erwin and Johnson (2000). Measurements of length (ABL, SBL) and width (TW) follow those of Ball (1972) and Kavanaugh (1979): ABL (apparent body length), measured from apex of labrum to apex of longer elytron; SBL (standardized body length), equals the sum of the lengths of the head (measured from apex of clypeus to a point on midline at level of the posterior edge of compound eyes), PL (pronotal length ), measured from apical to basal margin along midline, and LE (elytron length), measured from apex of scutellum to apex of the longer elytron; and TW (total width), measured across both elytra at their widest point with suture closed.
Included in this study are a total of 12 specimens from the National Museum of Natural History, Washington, DC (NMNH) in my charge, and a single paratype from the California Academy of Sciences (CASC, David H. Kavanaugh, Curator). The habitus images of the adult beetles portray most of the character states referred to in the key provided. Illustrations of male genitalia (modified from Vinson 1956 andWhitehead 1966) are standard for descriptive taxonomy of carabid beetles. The habitus images of the adults were made with a Visionary Digital TM high resolution imaging system. Figure captions include an ADP number, which is a unique identification number for the specimen that was illustrated or imaged and links the specimen and associated illustrations and/or image to additional information in electronic databases at the NMNH.
Geographical data are presented for species based on all known specimens available at the time of manuscript preparation, including those in the literature. Georeferences have been determined from locality information provided on specimen labels; only those exact georeferences that are provided on the label are placed in quotes, otherwise I have estimated these as closely as possible from places, mileage, etc. listed on the label and searched with Google Earth. Latitude and longitude are reported in decimal degrees. Here, English vernacular names are proposed, as common names are becoming increasingly needed in conservation and/or agricultural and forestry applications, and for the Encyclopedia of Life (www.eol.org). Habitat. Sea beaches and mangrove intertidal zone References. Bruneau de Miré (1979), Lorenz (2005), Peck (2006), Vinson (1956), Whitehead (1966) Note. The common name, Saline Catarrh Beetles, proposed here follows my principle of translating the scientific name as strictly as possible. In this case, "coryza" comes from the Greek, koryza, meaning cold, catarrh, as in disease. Why Alluaud named the genus so is not known.

Accounts of taxa
Diagnostic Combination. Differing in adult attributes from those of its adelphotaxon, Schizogenius Putzeys, 1846, by the following: Pygidium not striate or with very subtly crenulate striae; antennomere 2 pluristose. In addition, mandibles prominent, nearly straight laterally, abruptly angulate near apices; lacinia asetose on outer margin; frontal carinae nearly perfectly regular, parallel, equidistant, and equally raised; frons evenly convex; neck not pitted or punctate dorsally; eyes reduced, bordered laterally by a distinct carina; gula broad; mentum not deeply emarginate at middle, with median tooth obsolete and epilobes short; tarsi short; paramedian carinae of sternum II short, widely spaced and poorly developed; median lobe of male genitalia neither arcuate nor abruptly deflexed in apical third; fused stylus and coxite of the ovipositor with one robust seta (Whitehead 1966(Whitehead , 1972.
Geographic Distribution. Sea beaches, intertidal lagoons on the edges of mangroves, and island shores of the Atlantic, Indian, and Pacific Oceans, the Caribbean Sea, Sea of Cortés, and the Gulf of México.
Included Species. The species list below, as well as arrangement of descriptions that follow is ordered alphabetically. Whitehead, 1966 Ecuador; México

Microhabitat:
Adults are ground-dwelling on exposed wet substrate consisting of coquina-coral cemented by very fine silt or sand and covered with seaweed mats. Dispersal abilities: Wing-polymorphic: macropterous form probably capable of flight; brachypterous form, consequently flightless thus vagility limited to walking or running; both forms slow runners. seasonal occurrence: Adults have been found in March -April, July, and October. behavior: Adults are nocturnal predaceous halobionts and take cover in the sand or under drift and piles of seaweed on the beach. Populations of this species are associated with the centipede Pectiniunguis halirrhytus Crabill. In the northern part of their range, adults overwinter in the substrate; in the southern part, they likely aestivate during the dry season in the substrate.
References. Bruneau de Miré (1979), Nichols (1988, Ph.D. dissertation), Peck and Thomas (1998), Whitehead (1966Whitehead ( , 1969. Way of Life. Macrohabitat: Lowlands, sea level, in the intertidal zone of sea beaches. Microhabitat: Adults are ground-dwelling on coralline sands in the vicinity of coral reefs. Dispersal abilities: Wing-polymorphic: macropterous form probably capable of flight; brachypterous form, consequently flightless thus vagility limited to walking or running; both forms slow runners. seasonal occurrence: Adults have been found in January and October. behavior: Nocturnal predators, adults take cover during the day under dry seaweed just above the high water mark.
Way of life. Adults of other Halocoryza species are found on coralline sands in the intertidal zone of open beaches and among mangroves; a larva of the Indian Ocean species of this genus was found under dry seaweed just above the high-water mark on coralline sands. The single known specimen of H. whiteheadiana was collected at UV light on a sandy beach on the north shore of Isla Carmen, Baja California Sur. Adults of H. whiteheadiana are likely nocturnal halobiont predators, as are members of the other known species of this genus.
Other specimens examined. None.

evolutionary aspects
According to Whitehead (1966) and Vinson (1956) these beetles are strictly associated with coralline sands on open sea beaches, or in the intertidal zone of mangroves in the Indian, Atlantic, and Pacific Oceans, the Caribbean Sea, and the Gulf of Mexico. The recently discovered exception is H. whiteheadiana sp. n., described herein. It was found on the north shore of Isla Carmen in the Sea of Cortés. The nearest living reef to its type (and only known) locality is 350 km to the south at Bahia Pulmo. According to Markes E. Johnson (pers. comm.) the present sandy beaches on the north side of Isla Carmen "are exclusively carbonate sands derived from crushed mollusk shells." Therefore, the question arises: Has H. whiteheadiana undergone an ecological shift from coralline sands to crushed mollusk shell sands by way of evolving its more cylindrical and elongate form. Alternatively, is it a remnant species left over after more extensive corals that prehistorically occupied the more northern part of the Sea of Cortés became extinct? According to Johnson (pers. comm.), "fossil corals are to be found on Isla Carmen, and during the latest Pleistocene, "reefs", formed by Porities panamensis (Verrill) did develop at several localities on that island in Balandra Bay, Marquer Bay, and along the south end of the island. Pliocene corals are common, but I would not say they formed reefs …" Many south-facing beaches are composed of rhodolithic sand (Johnson and Ledesma-Vázquez 2009). While all of these types of beaches are derived from different animals (corals and mollusks), or red algae (rhodolithic), they all are fundamentally calcium carbonate. For Halocoryza species, it may be a case not of calcium carbonate, but rather of texture that is important, i.e. grain size and shape. Exploration of beaches on other islands and those near Bahia Pulmo are likely to produce more specimens (perhaps additional species); careful analysis of the sea-side substrate will be important to test the alternate suppositions made above, i.e. remnant species, or adaptive species. In addition, more specimens will test the hypothesis that this new species, like two others in the genus, is wing-polymorphic. Thanks to information provided by my good friend and colleague, Rick Brusca, and his colleagues Markes E. Johnson and Ramon Andres Lopez Perez, I now know that Isla Carmen has fossil coral deposits on it and that corals in the past were more extensive in the Sea of Cortés. Today, they occur in the waters off Isla Carmen, but do not form reefs there. Thus, species of the genus Halocoryza could be indicators of both present and/or past corals in the adjacent seas that are presently contributing, or have in the past, to the sandy mix of the beach on which they are found. Alternatively, H. whiteheadiana may represent a species that has undergone an ecological shift since the Pleistocene to an existence on another form of calcium carbonate, namely crushed mollusk shells. Determining if they also occur on the rhodolithic sands, (i.e. those of derived from coralline alga which are major contributors of CaCO 3 to beaches in the area) will require an additional sampling.