The coastal rove beetles ( Coleoptera , Staphylinidae ) of Atlantic Canada : a survey and new records

Th e coastline inhabiting rove beetles (Coleoptera: Staphylinidae) of Atlantic Canada are surveyed. Th irty-three species have now been recorded in Atlantic Canada including 26 in New Brunswick, 15 in Newfoundland, 31 in Nova Scotia, and 13 on Prince Edward Island. Oligota parva Kraatz, Acrotona avia (Casey), Strigota ambigua (Erichson), and Myrmecopora vaga (LeConte) are all newly recorded in Canada, and Bledius mandibularis Erichson is newly recorded in Atlantic Canada. We retain A. avia as a species distinct from A. subpygmaea Bernhauer and designate a lectotype for A. avia. Ten new provincial records are reported, one from New Brunswick, six from Nova Scotia, and three from Prince Edward Island. Four functional groups, halobiont (obligate), halophile (facultative), haloxene (tolerant), and incidental coastal species, are distinguished and the fauna is examined from the perspective of the particular coastline habitats and microhabitats they have been found to inhabit. Fourteen of the 33 staphylinids are introduced, Palearctic species, and eight of these have been associated with historical dry ballast shipping to the region from Great Britain. A trophic analysis indicates that some species are phytophagous algae feeders, while others are either generalist predators, or predators specializing on particular taxonomic or functional groups of invertebrates. Finally, some attention is devoted to discussing the diminished areas of coastline environments such as coastal marshes, and the various kinds of environmental disturbances and degradations they have experienced. Th ese indicate the potential vulnerability of such coastal habitats and consequently of the communities of beetles that inhabit them.


Introduction
While beetles are species rich and are ubiquitous in terrestrial and freshwater environments, only a relatively small number are found in marine situations.Amongst non-staphylinid beetles, Doyen (1976) listed 11 families (Carabidae, Hydrophilidae, Hydraenidae, Heteroceridae, Limnichidae, Melyridae, Salpingidae, Tenebrionidae, Rhizophagidae, Chrysomelidae, and Curculionidae) some species of which are obligate inhabitants of marine environments.Jeon and Ahn (2007) reported that 442 species of Staphylinidae in 102 genera and 7 subfamilies are known to be confi ned to seashore habitats, 0.93% of the circa 47, 744 described species of Staphylinidae (Herman 2001), and very close to the approximately 1% of rove beetles that Moore and Legner (1976) said were known to be confi ned to seashore habitats.Moore and Legner (1976: 521) wrote that, "Since habitat records are not known for the majority of staphylinids, it is not surprising if we are unaware of the marine habitat of some species".
In Europe there has been a considerable degree of attention to coastal Staphylinidae.Hammond (2000) published a thorough review of the British fauna based on extensive data sets.Fifty-eight species of halobiont, halophile, and halotolerant staphylinids are reported, with maps of each species in the British Isles, and 32 additional species occurring in coastal habitats, but not restricted to such environments, are also discussed for a total fauna of 90 species.A considerable degree of attention has also been paid to the coastal Staphylinidae of the Pacifi c coast of North America (Moore 1975, Moore andLegner 1976), however, comparatively little attention has been paid to the North American Atlantic coastal fauna.
Th ere has been some recent attention in the Maritime Provinces to seashore/coastline inhabiting Staphylinidae with the result that species such as Atheta novaescotiae and Atheta acadiensis have been newly described from the region, and species such as Brachygluta abdominalis have been newly recorded in Canada from such environments.Other characteristic coastline staphylinids such as Aleochara litoralis, Bledius spp., and Creophilus maxillosus have been noted in combination with a variety of other Coleoptera that characteristically inhabit coast-line, beach-drift, and sand dune ecosystems (Herman 1972(Herman , 1976;;Klimaszewski 1984;Majka and Ogden 2006;Klimaszewski et al. 2006;Klimaszewski and Majka 2007;Majka and Klimaszewski 2008).
Despite these studies of particular species or genera, relatively little research has been done on the Coleoptera of coastal environments in Atlantic Canada in general, and on the Staphylinidae in particular.In the present paper we survey coastline-inhabiting Staphylinidae of Atlantic Canada, newly recording a number of species in New Brunswick, Nova Scotia, Prince Edward Island, Atlantic Canada, and Canada as a whole.

Methods and conventions
A number of collections containing representatives of Staphylinidae collected in Atlantic Canada were examined and records of coastline-inhabiting species were compiled.Codens (following Evenhuis 2007) of collections referred to in this study are:

Results
Th e following species of Staphylinidae associated with coastal habitats have been recorded from Atlantic Canada.Th ere are two main categories of species; a) those that are regular members of coastal environments (halobionts, halophiles, and haloxenes); and b) incidental species that exhibit no specifi c coastal associations, but are generally attracted to decomposing situations, and hence are incidentally found in coastal environments.

Omaliinae
Micralymma marinum (Ström, 1785) NOVA SCOTIA: Guysborough Co.: Tor Bay, 6.V.1996, R.F.Lauff , intertidal zone, (1, NSMC).Th is species is newly recorded in Nova Scotia and its distribution in Atlantic Canada is shown in Fig. 12.It is a widely distributed Holarctic species found in intertidal habitats throughout Europe, Russia, Iceland, Greenland, Atlantic Canada, and New England in the USA (Larsson and Gígja 1959;Th ayer 1985;Böcher 1988;Campbell and Davies 1991;Downie and Arnett 1996;Herman 2001).Böcher (1988, 34) wrote, "M.marinum is a true marine insect, presumably spending its entire life cycle in the tidal zone, where it is regularly submerged at high tide.Adults and larvae are generally found together, on vertical parts or the underside of stones and rocks …".Adults and larvae are predaceous, feeding on Collembola such as Anurida maritima (Guérin-Méneville, 1836), mites, and Th ysanura although it is possible that larvae are, at least in part, also phytophagous feeding on algae (Th ayer 1985;Böcher 1988;Hammond 2000).

Pselaphinae
Brachygluta abdominalis (Aubé, 1833) Brachygluta abdominalis was reported in New Brunswick and Nova Scotia by Majka and Ogden (2006).Its distribution in Atlantic Canada and Maine is shown in Majka and Ogden (2006).Th e species is found in leaf litter in salt marshes and sand dune areas and in beach drift at the upper margin of the intertidal zone (Majka and Ogden 2006).Species of Brachygluta are specialist predators of mites (Hammond 2000).

Tachyporinae
Sepedophilus marshami (Stephens, 1832) Th is species was recorded from Nova Scotia by Campbell (1976) and from New Brunswick by Majka and Klimaszewski (2008).Its distribution in North America is shown in Campbell (1976) and in the Maritime Provinces by Majka and Klimaszewski (2008).Davies (1979) found this adventive Palearctic species in seaweed beach wrack in St. Andrews (NB), and Campbell (1976) reported it from "shore refuse".It has also been found in many forested, open, and fresh-water habitats and probably only occurs sporadically in coastline environments.Hammond (2000) includes it as a generalist species regularly reported from saline and intertidal situations in Great Britain.Aleochara litoralis was reported from New Brunswick, Newfoundland, and Nova Scotia by Klimaszewski (1984).Additional records are given above.Its distribution in the region of Atlantic Canada is shown in Fig. 12. Th e adults and larvae are found in decaying seaweed and debris on ocean beaches (Klimaszewski 1984).Aleochara adults are predators of larvae and eggs of cyclorrhaphous Diptera and ectoparasitoids of the pupae as larvae (Klimaszewski 1984).Th e specifi c hosts of A.  Oligota parva (Fig. 2) is newly recorded in Canada (Fig. 12).It has been previously recorded from California, Massachusetts, Missouri, and Texas (Moore and Legner 1975).It has been introduced to the western Palearctic and northern Africa and is now widespread there (Horion 1967;Smetana 2004).It is found in compost, on dung, in fermenting materials, in old hay and grass, and in other decomposing situations (Horion 1967).Th e ecology of Oligota species are not well known, however, at least some species prey on mites (Frank et al. 1992).While O. parva has not previously been reported as a beach drift species, all the specimens collected on Prince Edward Island were found in this habitat.One European species, Oligota pusillima Gravenhorst, 1806 has been recorded in decaying seaweed (Fowler 1888;Moore and Legner 1975).
Acrotona avia (Fig. 1) is newly recorded in Canada (Fig. 12).Acrotona avia was described by Casey (1910) on the basis of specimens collected in Rhode Island.Th e bionomics of the species are unknown, however, it appears that A. avia could be associated with sandy, seacoast environments.Pomquet Beach (45°39'27"N, 61°49'18"W) is a coastal barrier beach that lies between Pomquet Harbour and St. Georges Bay on the Gulf of St. Lawrence in Nova Scotia.Th e specimens from that locale were collected in a coastal sand dune environment adjacent to a "slack" (a temporary water body lying between two dune crests).Saunderstown (Rhode Island) is located near the mouth of Narragansett Bay where it opens up onto Long Island Sound.Th e Casey family farm (41°30'44"N, 71°25'23"W), where T.L. Casey lived and carried out collecting (Sikes 2004), is located 0.35 km from the seacoast, immediately adjacent to a barrier beach and coastal lagoon environment very similar to the Pomquet Beach site in Nova Scotia.Although there is no specifi c information that Casey collected the type specimens from precisely this site, it appears probable that A. avia is associated with such coastal environments.Cercyon litoralis (Gyllenhal, 1808) [Hydrophilidae] and Stenus erythropus Melsheimer, 1844 [Staphylinidae] were collected together with A. avia at Pomquet Beach.
Until this present report from Nova Scotia the species has not otherwise been reported from outside Rhode Island.It is likely that it is not as restricted in distribution as these limited records would appear to indicate, but rather as Sikes (2004: 10) pointed out, "…even in well-studied, temperate regions, a great deal of basic taxonomic work remains to be done".Gusarov (2001Gusarov ( -2003) ) listed this name as a junior synonym of Acrotona subpygmaea Bernhauer, 1909.However, we have specimens at hand from New Brunswick (see Kli- Bernhauer, which clearly belong to a diff erent species.For this reason we provisionally retain A. avia as a distinct species until proper revisionary studies are fi nalized.We confi rm however, that A. puritana (Casey, 1910) [originally Colpodota] is a junior synonym of A. avia (Casey).We were able to examine four syntypes of A. avia from Rhode Island, Boston Neck, housed in the Casey collection in Washington (USNM).We designate here the female bearing the following labels as the lectotype: "R.We have designated a female specimen as a lectotype because the female of this species may be easily distinguished by having the apical margin of sternite eight deeply emarginate (Fig. 11) and by the shape of the spermatheca (Fig. 9), and because the male genital structures were missing in the only male specimen in the type series.To avoid potential confusion in identifi cation of this species in the future we pro-   Gusarov (2001Gusarov ( -2003) ) reported this species from New Brunswick and Majka and Klimaszewski (2008) reported it from Nova Scotia and Prince Edward Island.Its distribution in the Maritime Provinces is shown in Majka and Klimaszewski (2008).Most of the specimens collected in Atlantic Canada are from agricultural fi elds, however, there are some records (above) from coastal habitats.Hammond (2000) includes it as a generalist species found in the upper levels of salt marshes in Great Britain.Strigota ambigua (Fig 3 .)is newly recorded in Canada (Fig. 12).It is widespread in the United States across a band from Connecticut, New York and New Jersey, south to North Carolina, west through Iowa, Missouri, Kansas, and Texas, to Colorado, New Mexico, Nevada, and California on the Pacifi c coast (Gusarov 2003).Almost nothing is known of the bionomics of this species.Gusarov (2001Gusarov ( -2003) ) recorded it from along riverbanks and in fl ood refuse.All the specimens found in the Maritime Provinces have been in sand dune and beach-drift environments.At Beaver River, NS other characteristic coastline species collected with S. ambigua include Hypocaccus fraternus, Stenus erythropus, Aegialia opifex Horn, 1887, and Blapstinus metallicus.For co-occurring coastline species found at Launching (PEI) see the preceding account on Oligota parva.Klimaszewski and Majka, 2006 NEW BRUNSWICK: Albert Co.: Mary's Point, 12.VIII.2004,C.G. Majka, ocean beach: beneath coastline drift, (3, CGMC).

Atheta novaescotiae
Atheta novaescotiae was described by Klimaszewski et al. (2006).Its distribution in Nova Scotia, Newfoundland, and the French territory of Saint-Pierre et Miquelon is shown in Klimaszewski et al. (2006).It is herein newly recorded in New Brunswick.It is found only in beach-drift environments at the upper end of the littoral zone on both sandy and rocky oceanic beaches in Atlantic Canada.For further information on co-occurring Coleoptera see Klimaszewski et al. (2006).Klimaszewski and Majka, 2007 Atheta acadiensis was described by Klimaszewski and Majka (2007) from beach-drift environments on oceanic beaches.Its distribution in New Brunswick, Nova Scotia, Québec, and Prince Edward Island is shown in Klimaszewski and Majka (2007).Majka et al. (in press) recorded it from under wrack on sea beaches on Scatarie Island, Nova Scotia.Specimens are found in the narrow and well-defi ned ecological zone within beach-drift material at the top of the littoral zone.For further information on co-occurring Coleoptera see Klimaszewski and Majka (2007).Atheta vestita is a Palearctic species newly recorded in North America from New Brunswick by Klimaszewski et al. (2006) in beach drift material.Its distribution in North America is shown in Fig. 13.In Scandinavia, the Baltic region, Great Britain, Greenland, Iceland, and the Faroe Islands this macropterous species is found almost exclusively on sandy and gravelly seashores where it occurs beneath decaying seaweed on the strand line (Lindroth 1931;Larsson and Gígja 1959;Böcher 1988), however, in the Faroe Islands it has also been reported from grassland and waste land environments close to the seashore (Bengtson 1981).Given the maritime biology of this species, and the distribution of this species around the margins of the North Atlantic, further investigations should be conducted in Atlantic Canada and New England to determine the extent of its distribution and to examine whether it might be a naturally-occurring Holarctic species.Erichson, 1839Hoebeke (1985) recorded this species from New Brunswick and Nova Scotia.Davies (1979) found it in seaweed beach wrack in St. Andrews, New Brunswick.Howden (1970) and Wright (1989) recorded it from pond-edge debris on Sable Island, NS, and Hoebeke (1985) noted that it occurs in beach debris.Its distribution in Atlantic Canada is shown in Fig. 13.Hoebeke (1985) erroneously plotted the Sable Island (160 km off the Atlantic coast of Nova Scotia) records as being from Cape Sable Island (in southwestern Nova Scotia).It is a species found in many decompositional situations (Hoebeke 1985) that only occurs sporadically in coastline environments.Myrmecopora vaga (Fig. 4) is newly recorded in Canada (Fig. 13).Th e specimen was collected on a small sandy beach along the Northwest Arm in Point Pleasant Park.Several individuals were observed in the vicinity of beach-drift detritus accumulated at the top of the strand line.Th ey were, however, quick to take fl ight and agile on the wing, and only one specimen was captured.Other characteristic co-inhabiting coastline species of beetles collected together with M. vaga at this site were Cercyon litoralis, Dermestes undulatus Brahm, 1790 [Dermestidae], and Blapstinus metallicus.Myrmecopora vaga was described by LeConte (1866) from the "Lake Superior" region of the United States where it was found in the riparian areas of lakes and streams (Newton et al. 2000).Th e present record is the fi rst subsequent record, and the fi rst one from eastern North America.While the species was found in riparian areas in the interior of the continent, it was discovered on the coastline in Nova Scotia.Th is may be a typical habitat for this little-known species given that many Western Palaearctic species of Myrmecopora are known to inhabit coastline, beach-drift, and shingle-beach environments where they are typically found beneath seaweed and other debris accumulated on the strand line (Assing 1997a(Assing , 1997b)).Th ese include M. fugax (Erichson, 1839), M. laesa (Erichson, 1839), M. uvida (Erichson, 1840), M. boehmi Bernhauer, 1910, M. oweni Assing, 1997, M. sulcata (Kiesenwetter, 1850), M. simillima (Wollaston, 1864), M. maritima (Wollaston, 1864), M. minima Bernhauer, 1900, M. anatolica (Fagel, 1969), M. bernahueri Koch, 1936, andM. brevipes Butler, 1909 (all the species in the subgenera Iliusa, Paraxenusa, and Xenusa); and in the eastern portion of the Palaearctic region, M. rufescens (Sharp, 1874), M. algarum (Sharp, 1874), M. reticulata (Assing, 1997), and M. chinensis Cameron, 1944 (all the species in the subgenus Lamproxenusa).Consequently this species should be sought more extensively in both riparian and seacoast situations in North America in order to better determine its distribution on the continent.Bledius basalis is newly recorded in New Brunswick.Its distribution in Atlantic Canada is shown in Fig. 14.Herman (1976) indicated that the species was found in coastal habitats from Texas north to Rhode Island.Howden (1970) recorded the species from Sable Island (Nova Scotia), the only previously known Canadian location.Th e above specimens collected from Petpeswick and Melveryn Square establish the occurrence of this species on the mainland of Nova Scotia.

Bledius basalis
All the sites where this species has been recorded in the United States are coastal and most are slightly moist, slightly vegetated sand fl ats adjacent to the ocean (Herman 1976).Th is is true of Petpeswick, a sandy inlet on the Atlantic coast of Nova Scotia.Melveryn Square, however, lies in the Annapolis Valley of Nova Scotia, although it is only 9 km from "Sand Banks", a sandy coastal beach on the Bay of Fundy, and B. basalis is macropterous and a capable fl ier.Jemseg (New Brunswick) is 70 km inland from the Bay of Fundy, however, it is located on the shores of Grand Lake, which at 174 km 2 , is the largest freshwater body in Atlantic Canada.Th is would ap-pear to indicate that B. basalis, while occurring predominantly in coastal localities, can also be found in appropriate inland sites away from the ocean.Bledius mandibularis is newly recorded in Nova Scotia and Atlantic Canada.Its distribution in Atlantic Canada is shown in Fig. 14.In North America there are two populations; a coastal one occurring from southern Texas to Massachusetts, and an inland one found in the central regions of the United States, north to southern Manitoba (Herman 1972).Th e coastal population is found on bare, moist ground in saline habitats, generally on the leeward side of islands or peninsulas and behind beach dunes (Herman 1972).Backmans Beach is a small island at the tip of the Second Peninsula in Lunenburg County which is linked to the mainland via a barrier beach.It has six variously sized barrier beach-coastal lagoon areas with associated marshlands and sand fl ats.Herman (1976) recorded this species from Newfoundland, Nova Scotia (the Atlantic coast), and the French territory of Saint-Pierre et Miquelon.Its distribution in Atlantic Canada is shown in Fig. 14.Campbell and Davies's (1991) checklist included the species from New Brunswick without, however, providing any records.Th e above records establish its presence in New Brunswick and indicate that the species occurs on both the Nova Scotia and New Brunswick shores of Bay of Fundy.It is found on moist, un-vegetated sand fl ats on the leeward sides of islands and peninsulas, as well as in the intertidal zone.It has been collected in the region in association with the predaceous carabids Dyschirius sphaericollis Say and Dyschirius pallipennis Say (Herman 1976).

Bledius opaculus LeConte, 1877
NOVA SCOTIA: Halifax Co.: Sable Island, 22. VII.1976, 13.VI.1977, 14.VI.1977,wet sand at the edges of ponds, B. Wright, (6, NSMC).PRINCE EDWARD ISLAND: Queens Co.: Cavendish Beach, 22.VII.1967, H.F. Howden, (1, CNC).QUÉBEC: Iles de la Madeleine, 7-9.VII.1992,F. Shaeff er and P. Laporte, 322 specimens, Majka and Shaff er (in press).Herman (1976) recorded this species from Newfoundland, Nova Scotia (Sable Island), and Prince Edward Island (Fig. 14).In Nova Scotia the species has only been recorded from Sable Island (Howden 1970, Wright 1989).More recently Majka and Shaff er (in press) recorded large numbers in the diet of Piping Plovers in the Iles de la Madeleine, Québec, newly recording the species from that province.Herman (1976) found the species on moist, un-vegetated sand fl ats on the leeward side of an island and on algae covered moist sand fl ats.On Sable Island specimens have been found associated with dead gulls, in large swarming groups along the shores of Wallace Lake, and on wet sand at the edge of small ponds (Wright 1989).In the Iles de la Madeleine they are found on moist sand fl ats in the lee of large barrier beaches (Majka and Shaff er in press).Th e species' distribution in Atlantic Canada is shown in Fig. 14.
Bledius politus was recorded from New Brunswick by Campbell and Davies (1991) on the basis of the record above (shown in Fig. 14).It is associated with coastal areas, as well as inland swamps and lakes, and is found in slightly moist, heavily vegetated sand (Herman 1976).Stenus erythropus is newly recorded on Prince Edward Island.Its distribution in Atlantic Canada is shown in Fig. 13.It was previously recorded from New Brunswick and Nova Scotia (Campbell and Davies 1991).Stenus erythropus is not a species hitherto noted from coastal habitats, and indeed there are a number of specimen records in the Maritime Provinces from inland, non-marine situations (unpublished data).Like many species in this genus they are frequently encountered near streams or in other aquatic situations (Newton et al. 2000).As the above records indicate, in the Maritime Provinces they are occasionally found in coastal marshy and/or sand dune environments.LeSage, salt marsh, pile of decaying vegetation, (1, CNC).Majka and Klimaszewski (2008) reported this species from New Brunswick.Its distribution in Atlantic Canada is shown in Fig. 13.Ochthephilum fracticorne has not been noted in Europe as a coastal species but rather is regarded as a synanthropic one found in fi elds, parks, litter, decomposing hay, and compost (Drugmand 1989).D.S. Chandler (pers.comm.) has recorded it coastal habitats in New Hampshire and the above records from New Brunswick and Nova Scotia indicate that it is at least an occasional inhabitant of such environments (Fig. 13).Ochthephilum jacquelini (Boieldieu, 1859), however, is a halobiont found exclusively in salt marshes in Great Britain (Hammond 2000).Th ere is some uncertainty about the zoogeographic status of O. fracticorne.Campbell and Davies (1991) listed it as a Holarctic species but Drugmand (1989) treated it as a Palearctic species.

Gyrohypnus angustatus Stephens, 1832
Th is species was recorded from New Brunswick, Newfoundland, and Nova Scotia by Smetana (1982).Davies (1979) found this introduced Palearctic species in seaweed beach wrack in St. Andrews, New Brunswick.Its distribution in Atlantic Canada is shown in Fig. 15.Smetana (1982) noted rotting seaweed as one of the habitats where the species has been found in North America and Lindroth (1957) found it at every one of the southern English coastal sites that he surveyed where dry ballast destined for North America originated.Th is not only indicates habitat preferences, but also a possible mechanism for the introduction of this species to North America.orchestia megalophthalma (Bate, 1862), O. platensis Kroyer, 1845, andO. grillus (Bosc, 1802) are also present in the region (Gosner 1971).

Philonthus cognatus
Philonthus cognatus is an introduced Palearctic species, widely distributed in both eastern and western North America (there are few records from the central portions of the continent).Its distribution in North America is shown in Smetana (1995).Smetana (1995) records it from a wide range of habitats.Hammond (2000) includes it as a generalist species found in the upper levels of salt marshes in Great Britain.It is a common species in Atlantic Canada and there are some records from coastal environments (Wright 1989), however, it is primarily found in synanthropic inland situations.Hatch, 1957 NOVA SCOTIA: Halifax Co.: Sable Island, 5-12.VII.1967, H. Howden, (1, CNC); Victoria Co.: Dingwall, 20.IX.1984, J.M. Campbell and A. Davies,(1,CNC).Smetana (1995: 331) wrote, "Philonthus couleensis is a pronouncedly hygrophilous species, occurring in a wide variety of wet habitats … even in marshy habitats along sea beaches".Th ere are scattered records in New Brunswick, Newfoundland, and Nova Scotia (Smetana 1995) including a few from coastal habitats.Its distribution in North America is shown in Smetana (1995).Smetana (1995: 96) wrote, "Philonthus furvus is a distinctly hygrophilous species, occurring in all kinds of wet habitats, such as edges of lakes and ponds, marshes and swamps, banks of rivers and creeks, wet forests, seepages, etc." Davies (1979) found this species was apparently well-adapted to, and dependant on, beach-wrack environments in St. Andrews, New Brunswick.Th e above records from Brier Island (NS) are from a similar environment.Its distribution in North America is shown in Smetana (1995).VI.1977, 15.VI.1977, B. Wright, (4, NSMC).

Philonthus politus (Linnaeus
Philonthus politus is found in all kinds of decaying organic matter (Smetana 1995).It is not particularly associated with coastal habitats.Th ere are scattered records in New Brunswick, Newfoundland, and Nova Scotia (Smetana 1995) including a few (above) from coastal habitats.Its distribution in North America is shown in Smetana (1995).(Gravenhorst, 1802) NOVA SCOTIA: Victoria Co.: Ingonish Beach, 27.IX.1974, A. Davies, (1, CNC).Smetana (1995) observed that this species is found in a wide range of habitats.Davies (1979) found this species was frequent in coastal beach-wrack habitats, but also found in other environments, in St. Andrews, New Brunswick.It has not been noted as a coastal species in Great Britain (Hammond 2000).Its distribution in North America is shown in Smetana (1995).

Philonthus varians (Paykull, 1789)
PRINCE EDWARD ISLAND: Prince Co.: Belmont Park, 9. VII.1988, Y. Bousquet, (1, CNC).Davies (1979) found this introduced Palearctic species in seaweed beach wrack in St. Andrews, New Brunswick.According to Smetana (1995: 240) "Philonthus varians occurs in all kinds of decaying organic matter … specimens were also collected under rotting seaweeds on sea beaches …".It is abundant in many portions of the Atlantic Provinces (Smetana 1995;unpublished data).Its distribution in North America is shown in Smetana (1995).It was fi rst recorded in the region in New Brunswick in 1900-1907(Majka and Klimaszewski 2008).Hammond (2000) includes it as a generalist species regularly reported from saline and intertidal situations in Great Britain.

Discussion
Th irty-three species of coastline inhabiting Staphylinidae have now been recorded in Atlantic Canada.Th ese include 26 species recorded in New Brunswick, 15 in Newfoundland, 31 in Nova Scotia, and 13 on Prince Edward Island (Table 1).Oligota parva, Acrotona avia, Strigota ambigua, and Myrmecopora vaga, are newly recorded in Canada and Bledius mandibularis is newly recorded from Atlantic Canada.Ten new provincial records are reported, one from New Brunswick, six from Nova Scotia, and three from Prince Edward Island.Th ey include representatives of eight subfamilies and 21 genera.

Excluded species
Delimiting the composition of coastal staphylinid communities is much more complicated than might fi rst appear to be the case (see below).Th e biology of many staphylinids is poorly or incompletely known making it diffi cult to ascertain to what degree they may be members of coastal beetle communities.Many species of rove beetles are attracted to decomposing plant or animal material, and some coastal environments have large quantities of such materials.Others, associated with fl ood debris, or hygrophilous   In Great Britain, Hammond (2000) drew attention to species such as Amischa analis (Gravenhorst, 1802), Atheta longicornis (Gravenhorst, 1802), Quedius curtipennis Bernhauer, 1908, Quedius molochinus (Gravenhorst, 1806), and Bisnius cephalotes (Gravenhorst, 1802) as incidental species found in salt-marshes and other intertidal habitats.Similarly Moore and Legner (1976) reported Drusilla canaliculata (Fabricius, 1787) from under decaying seaweed in Great Britain, Newton et al. (2000) reported Tasgius melanarius (Heer, 1839) from under debris near water, including in marine situations, and Smetana (1995) reported Philonthus concinnus (Gravenhorst, 1802) from a variety of habitats including under seaweed on sea beaches.All these Palearctic species are found in Atlantic Canada (Majka and Klimaszewski 2008), however, none of them have been recorded in such habitats in the Atlantic Provinces.Th ey are all species generally associated with soil and litter environments and/or decaying material, and therefore only peripheral members of coastal environments.In this preliminary treatment of the coastal rove beetles of Atlantic Canada they have therefore not been included in the coastal fauna, although it is clear that further research is required to fully delineate the faunal composition of coastline environments.

Adaptations to the marine environment
Staphylinids found in coastal environments can be categorized in four functional groups (adapted from Koch 1989-1993and Hammond 2000): A) Halobionts: Obligate inhabitants of coastline environments, i.e., species that are largely or completely restricted to such habitats; B) Halophiles: Facultative inhabitants of coastline environments, i.e., those that regularly occur in coastline habitats but can also be found in non-marine situations; C) Haloxenes (or halotolerants): species that principally occur in other inland environments, but are also found in coastline habitats and are (in varying degrees) tolerant of conditions in such habitats; D) Incidentals: species that exhibit no specifi c coastal associations, but are attracted to decomposing situations or marshy or otherwise wet environments, and which are thus regularly found in coastal environments where such conditions exist.
Th e delineation between these categories is not without some uncertainty since, as previously mentioned, the bionomics of some species are incompletely known.Based on published information and data from specimens collected in the region a provisional categorization indicates that 11 species found in Atlantic Canada can be categorized as halobionts, seven as halophiles, six as haloxenes, and nine as incidental species.
As previously mentioned, there is no simple delineation between coastal and noncoastal species, given the fact that terrestrial ecosystems grade into marine ecosystems along a continuum (indeed, coastline environments are by defi nition an ecotone) and contain microhabitats that attract and support terrestrial species.In delimiting the fauna, however, studies such as these by Topp and Ring (1988a,b) are of considerable value.In examining the ecology and physiology of Pacifi c-coast marine Staphylinidae found on sandy and rocky shorelines, they were able to demonstrate a suite of specifi c morphological, behavioral, and physiological adaptations to immersion by seawater and desiccation that allowed the marine species to survive in such environments.Th ese include sheltering in burrows or crevices which hold air pockets during inundation (Bledius spp., Liparocephalus cordicollis, Diulota densissima); taking fl ight when inundated by seawater (Bledius monstratus), holding a bubble of air around the thorax and abdomen with a plastron on fi ne hairs on the body surface (B.monstratus) which acts as a "physical gill" to supply air to the spiracles; fl oating on the surface fi lm of water when inundated (Th inopinus pictus); becoming catatonic in conditions of anoxia, thus slowing physiological processes allowing for longer survival in conditions of immersion (Cafi us canescens, Cafi us seminitens, Hadrotes crassus); and utilizing dissolved oxygen through cutaneous respiration through membraneous portions of the exoskeleton (L.cordicollis).Such morphological, behavioral, and physiological adaptations contrast with those of terrestrial species and are refl ected in the LT 50 (median lethal time) values for seawater immersion of such species.At 10°C, LT 50 values were 12-16 hours for C. canescens, 12 hours for T. pictus, and 18 hours for B. monstratus while rocky-shore species such as D. densissima had LT 50 values of 26 ± 4 days and L. cordicollis 25.5 ± 9.5 days.Th is is in contrast to species such as T. ater, which had an LT 50 value of 2 hours (Topp andRing 1988a, 1988b).Such research indicates that detailed morphological, behavioral, and physiological studies of coastline inhabiting beetles could be used to distinguish between obligate, facultative, tolerant, and incidental species.

Coastal environments and their staphylinid faunas
Coastal environments are themselves diverse and include a number of discrete habitats and zones.In the Maritime Provinces they include: i) rocky shores, ii) boulder/ cobble shores, iii) sandy shores, iv) mud fl ats, v) tidal marshes, and vi) sand dune systems (Davis and Browne 1996).Some of these environments (such as rocky, boulder, and sandy shores) are further stratifi ed into i) splash zone, ii) upper littoral, iii) midlittoral, and iv) lower littoral zones; mudfl ats and tidal marshes sometimes grade into successional sequences and diff erentiate into high and low salt-marsh areas; and sand dunes are diff erentiated into i) colonizing zone, ii) yellow dune, and iii) grey dune areas (Davis and Browne 1996).Further variation is created by the intersection of these coastal habitats and the presence of microhabitats (such as brackish-water "slacks" between dune crests).Consequently coastal environments represent a diverse constellation of habitats and microhabitats that can provide for a large number of ecological niches that can be utilized by coastal beetles.
This diversity is reflected in the coastal staphylinid fauna found in Atlantic Canada.Micralymma marinum is a true marine species found in the littoral zone on rocky coastlines.Species of Bledius inhabit sandy mudflat environments.Large rove beetles such as C. m. villosus and Tasgius spp.tend to shelter under stones or driftwood in the splash zone or upper littoral areas from where they venture into strand-line areas.Philonthus spp.and many aleocharines are primarily found associated with decaying seaweed and other organic materials deposited by tidal action at the upper end of the littoral zone.Brachygluta abdominalis is found in leaf litter in salt marsh and sand dune areas, and Stenus erythropus inhabits wet, marshy habitats.
An admittedly fi rst-order summary of the habitat types and microhabitats within each of these, that are favoured by the coastal staphylinids found in Atlantic Canada, is presented in Table 1.Th ese categories are derived from those employed by Hammond (2000) in his analysis of the British coastal fauna.In the case of some species such as M. marinum, B. abdominalis, A. litoralis, A. novascaotiae, A. acadiensis, A. vestita, Bledius spp., C. maxillosus, T. ater, and C. bistriatus, there has been suffi cient research conducted that at least some elements of the bionomics of these species are comparatively well known.In the case of others such as O. parva, A. avia, S. ambigua, M. vaga, and S. erythropus, very little is known of the biology of the species so the information in Table 1 is of necessity based on limited data.Nonetheless the compilation is instructive since it illustrates that the coastal staphylinids appear to fall into fi ve ecological groups: 1) rocky shore species (M.marinus) 2) salt marsh, leaf-litter species (B.abdominalis) 3) species found around dune slacks (A.avia, S. erythropus) 4) sand/mud-fl at inhabitants (Bledius spp.) 5) tidal debris (beach-drift ) species (other species) Amongst the tidal debris species, some appear to favour sandy shores or salt marshes, while others (the "SE" seashore category) are found on sandy, rocky, or cobble shores wherever beach-drift accumulates.
From a trophic perspective, Bledius spp.are nocturnal feeders and harvest green algae such as Oocystis solitaria Wittr., Oocystis parva West., Anchistrodesmus falcatus Ralfs, and Conferva minor Klebs), blue-green algae such as Oscilitoria amphibia Ag. and Anabaena sp., and diatoms (species undetermined) from the mud or sand surface, storing them in chambers excavated in the mud where the females lay eggs and rear young (Lengerken 1929;Herman 1986).Other species of coastline staphylinids are (insofar as is known) primarily predaceous, however, the size of the species and the habitats they occupy mean that they utilize a variety of prey species.Most coastal staphylinids feed on amphipods, larvae of seaweed fl ies such as Fucellia sp., or enchytraeid worms such as Lumbricillius sp. and Enchytraeus (Moore and Legner 1976;Top andRing 1988a, 1988b).Large Staphylininae such as C. maxillosus, Tasgius spp., and Philonthus spp.are generalist predators (Smetana 1995;Newton et al. 2000) that in beach drift habitats probably feed on Diptera larvae as well as on other invertebrates.Aleochara litoralis is also a predator of larvae and eggs of cyclorrhaphous Diptera (Klimaszewski 1984).Cafi us bistriatus is predaceous on amphipods, fl y larvae, and small barnacles (James et al. 1971).Micralymma marinum and species of Stenus, such as S. erythropus, prey on Collembola and other micro-arthropods (Th ayer 1985;Böcher 1988;Newton et al. 2000).Brachygluta abdominalis and Oligota species are predators of mites (Acari) (Frank et al. 1992;Hammond 2000).While the bionomics of other species of coastline aleocharines are incompletely known, most are believed to be microfauna predators.

Adventive species
Th e substantial proportion of adventive Palearctic species represented in this ecological group is noteworthy.As many as 13 species (the zoogeographic status of O. fracticorne and A. vestita are still subject to some questions), or 39% of the coastal species, are adventive species.Th ese are principally the members of the Staphylininae, indeed of the 13 species in this subfamily, only C. bistriatus, P. couleensis, and P. furvus are native North American species.Brown (1940Brown ( , 1950) ) and Lindroth (1957) both proposed that many species of adventive plants and invertebrates were introduced to Atlantic Canada in dry ballast that was shipped to the region during the Napoleonic wars and subsequently when Great Britain was importing large quantities of timber from the region.Empty ships traveling westward across the Atlantic were ballasted with sand, rocks, rubble, soil, etc., originating from coastal quarries.Th is dry ballast was subsequently off -loaded on land in Atlantic Canadian ports, and with it a plethora of species that were found in such coastal sites.Of the 13 adventive coastal staphylinids found in Atlantic Canada, eight (M.fungi, A. vestita, G. angustatus, T. ater, G. astutoides, P. carbonarius, P. cognatus, and P. varians) were found by Lindroth (1957) in quarries in south-western England where dry-ballast destined for Atlantic Canada originated, a suggestive indication that these species may have been introduced to the region via this mechanism.Indeed, all 13 adventive species of staphylinids are found in Great Britain.

Conservation concerns
Coastline beetles inhabit an environment that has been much diminished and is vulnerable to disturbance.Of the estimated 35,700 hectares of coastal marshes present in the Bay of Fundy at the time of European colonization, only 5,000-6,000 (~ 16%) are still extant.Fifty-seven percent of large and medium-sized rivers that fl ow into the Bay of Fundy have dams, causeways, and other forms of tidal restrictions and coastal wetlands have experienced various other forms of environmental degradation (Percy 1996(Percy , 1999)).Rantwell (1972) emphasized that coastal sand dunes are a diminishing resource throughout Europe and North America saying, "Not only is their generation limited by what is believed to be a diminishing bank of off shore sand supplies, but their rate of destruction under development of various kinds ... almost certainly (exceeds) their rate of formation".Tyrrell (2005) pointed out that on some beaches, large quantities of seaweed and other detritus are removed from the wrack line to "clean up" beaches for recreation or tourism.Orth et al. (1978) and Frank et al. (1986) have both noted the negative eff ects of such "beach cleaning" on seashore insect assemblages.All these observations draw attention to the potential vulnerability of such coastal habitats and communities of beetles that inhabit them.
With the discovery of Oligota parva, Acrotona avia, Strigota ambigua, Myrmecopora vaga, and Bledius mandibularis in Nova Scotia (four of which are newly recorded in Canada) it is apparent that there is much more to learne with respect to the Staphylinidae that inhabit coastline environments in Atlantic Canada.
litoralis have not previously been documented, however, C.G. Majka has collected Coelopa frigida (Fabricius, 1805) (Diptera: Coelopidae), a common and widespread Holarctic fl y, in Point Pleasant Park in association with A. litoralis.Adults, larvae, and pupae of this fl y were very numerous in the decomposing seaweed and are presumably the prey species utilized by A. litoralis.Oligota parva Kraatz, 1858 PRINCE EDWARD ISLAND: Kings Co.: Launching, 26.VIII.2003,C.G. Majka, ocean beach: under coastline drift at the top of the littoral zone, (4, CGMC).

e
coastal rove beetles(Coleoptera, Staphylinidae)  of Atlantic Canada: a survey and new records 133 Fig. 15.Th e distribution of Gyrohypnus angustatus, Creophilus maxillosus villosus, Cafi us bistriatus, and Gabrius astutoides in Atlantic Canada.Note: Two sites from central Labrador (Goose Bay and Cartwright) are not shown on the map.