Research Article |
Corresponding author: Kee-Jeong Ahn ( kjahn@cnu.ac.kr ) Academic editor: Volker Assing
© 2022 In-Seong Yoo, J. H. Frank, Jong-Kuen Jung, Kee-Jeong Ahn.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Yoo I-S, Frank JH, Jung J-K, Ahn K-J (2022) Integrative taxonomy of coastal Cafius bistriatus (Erichson) species complex (Coleoptera, Staphylinidae). ZooKeys 1100: 57-70. https://doi.org/10.3897/zookeys.1100.79435
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A systematic review of the marine littoral Cafius bistriatus (Erichson) along the eastern Pacific and the western Atlantic coasts including the Caribbean Sea is presented based on morphological and molecular (COI and 28S) characters. Specimens of the Cafius bistriatus species complex [C. bistriatus, C. rufifrons Bierig, and C. sulcicollis (LeConte)] are similar to each other, including the form and structure of the aedeagus, and they can be treated as cryptic species. Detailed micromorphological characters (SEM) and molecular analyses support the validity of these three species. Intraspecific genetic divergence of COI using uncorrected p-distance among individuals of Cafius bistriatus ranged from 0% to 1.56%, while interspecific divergence among three species ranged from 4.90% to 14.59%. All three species were each supported as a single lineage using COI and 28S on both parsimony and maximum likelihood trees. Morphological characters among C. bistriatus, C. rufifrons, and C. sulcicollis are compared. Cafius bistriatus fulgens Frank is synonymized under C. bistriatus and Cafius bistriatus is redescribed with illustrations of diagnostic characters.
Cafius, coastal, COI, cryptic, 28S, rove beetles, Staphylinidae, taxonomy
The marine littoral species Cafius bistriatus (Erichson) occurs along the coasts of eastern Pacific and the western Atlantic including the Caribbean Sea and is known to be predaceous on invertebrates in decaying seaweeds on sandy beaches (
During a taxonomic revision of the genus Cafius, we recognized that C. bistriatus, C. rufifrons Bierig, and C. sulcicollis (LeConte) may be the same species. They are very similar in external form and internal structure including the male genitalia. Hereafter, we will refer to them as the C. bistriatus species complex (Fig.
We studied about 250 specimens of Cafius bistriatus species complex (C. bistriatus, C. rufifrons, and C. sulcicollis) collected from a broad geographic distribution (Fig.
In this paper, we compared morphological and molecular characters among individuals of the C. bistriatus species complex and redescribed C. bistriatus with illustrations of diagnostic characters.
For the study of morphological characters, we selected many specimens with different geographic distributions for their intraspecific variation, and dissected and cleared the whole body for examining microstructures (
For the study of molecular characters, we included a total of 18 specimens (18 for COI and 17 for 28S) for DNA extraction in the dataset and the specimens studied are listed in Table
List of species with their locality data and GenBank accession numbers. Asterisks and dashes indicate new addition and missing regions, respectively.
Species | Collection locality | COI | 28S |
---|---|---|---|
Cafius bistriatus 1 | USA: Florida, Levy Co., Cedar Key | *OK398364 | *OK398345 |
Cafius bistriatus 2 | USA: Florida, Monroe Co., Bahia Honda Key | *OK398365 | *OK398346 |
Cafius bistriatus 3 | USA: Florida, Levy Co., Cedar Key | *OK398366 | *OK398347 |
Cafius bistriatus 4 | USA: Florida, Levy Co., Cedar Key | *OK398367 | *OK398348 |
Cafius bistriatus 5 | USA: New Hampshire, Rockingham Co. | *OK398368 | *OK398349 |
Cafius bistriatus 6 | USA: Florida, Monroe Co., Florida Keys | *OK398369 | *OK398350 |
Cafius bistriatus 7 | USA: Florida, Monroe Co., Florida Keys | *OK398370 | *OK398351 |
Cafius bistriatus 8 | USA: Florida, Monroe Co., Bahia Honda Key | *OK398371 | *OK398352 |
Cafius bistriatus 9 | USA: Florida, Monroe Co., Bahia Honda Key | *OK398372 | *OK398353 |
Cafius sulcicollis 1 | USA: California, Santa Barbara | *OK398373 | *OK398354 |
Cafius sulcicollis 2 | USA: California, Santa Barbara | *OK398374 | – |
Cafius sulcicollis 3 | USA: California, Santa Barbara | *OK398375 | *OK398355 |
Cafius sulcicollis 4 | USA: California, Rufugio State Beach | *OK398376 | *OK398356 |
Cafius sulcicollis 5 | USA: California, Rufugio State Beach | *OK398377 | *OK398357 |
Cafius sulcicollis 6 | USA: California, Gaviota State Beach | *OK398379 | *OK398358 |
Cafius sulcicollis 7 | USA: California, San Simeon | *OK398378 | *OK398359 |
Cafius rufifrons 1 | USA: Florida, Monroe Co., Keywest | *OK398380 | *OK398360 |
Cafius rufifrons 2 | USA: Florida, Monroe Co., Keywest | *OK398381 | *OK398361 |
Cafius histrio 1 | KOREA: Chungnam, Taean | MW407895 | MW406746 |
In total, 35 new sequences from USA (California, Delaware, Florida, New Hampshire, North Carolina, and Puerto Rico) were generated (836 bp of partial COI gene region and c. 1034 bp of partial 28S). All new sequences were deposited in GenBank (accession numbers: OK398364–OK398381 for COI and OK398345–OK398361 for 28S in Table
Intraspecific genetic divergence of COI using uncorrected p-distance among individuals of Cafius bistriatus ranged from 0% to 1.56%, while interspecific divergence among three species ranged from 4.90% to 14.59% (Table
Inter- and intraspecific genetic differences in Cafius bistriatus, C. rufifrons, and C. sulcicollis for COI (836 bp) calculated using p-distance.
C. bistriatus | C. rufifrons | C. sulcicollis | |
---|---|---|---|
C. bistriatus | 0–1.56 | ||
C. rufifrons | 11.72–14.59 | 0 | |
C. sulcicollis | 4.90–6.10 | 13.76–14.59 | 0.12–1.20 |
Cafius Stephens, 1829: 23 (Type species: Staphylinus xantholoma Gravenhorst).
Philonthus bistriatus
Erichson, 1840: 502. [Type locality: Americae septentrionalis Insula Longa (Long-Island); 1 syntype in
Philonthus bilineatus
Erichson, 1840: 503. [Type locality: Americae meridionalis Insula Antiguae, St. Johannis (St. John’s, the capital of Antigua); 1 syntype in
Cafius bistriatus fulgens
Frank, 1986: 153 [in
1 syntype, “6155 || bilineatus | Typus | Er. f. 503. || Antigua | Moritz 5.5 || Philonthus | bilineatus || = bistriatus Er.” (
Canada: 6 exx., Nova Scotia, Cape Breton H. N. P. Presqu’île, 3 m, PG562728, 13.IX.1984\J. M. Campbell & A. Davies, sifting beach wrack; 1 ex., Nova Scotia, Cape Breton H. N. P. Ingonish N. Bay, PG984711\29.VI.1983, L. LeSage, LL54 TP18, seashore wrack; 2 exx., Nova Scotia, Cape Breton H. N. P. Pleasant Bay\27.V.1984, L. Masner, seabeach kelp; 2 exx., Nova Scotia, Cape Breton H. N. P. Pleasant Bay, seashore kelp\29.VII.1983, D.E., J.E. Bright pans; 4 exx., N. S. Cape Breton Highl. N. P. 25 km SE Cap Rouge, 14.VI.84, A. Smetana; 1 ex., C. I.\Schwarz; 1 ex., New Brunswick, Passamaquoddy Bay, Pottery Bch., 29.VII.1976, M.J. Dadswell; 1 ex., New Brunswick, Passamaquoddy Bay, Pottery Bch., 29.VII.1976, M.J. Dadswell; 1 ex., QUE: St. Adelaide 0.5 mi. W. Sandy Beach Stn., 21.VIII.1953, E.L.Bousfield; 3 exx., QUE., 4 mi. S. Riviėre-à-Claude, VII-18-1972, 200’, J.M. Campbell; 5 exx., N. S. Point Aconi, VIII-13-1972, J.M. & BA Campbell; 5 exx., N. S. Big Bras d’Or, VII-25-1972, J.M. Campbell; 1 ex., Kouchibouguac N. P., N. B., 1.VI.1977, S.J. Miller, Code-5195U\Cafius bistriatus Er. Det. J.M. Campbell 1978; 1 ex., Kouchibouguac N. P., N. B., 13.IX.1977, J.M. Campbell, Code-5953Y. Jamaica: 2 exx., JA., Clarendon P., Jackson’s Bay, 12.XII.1972, J. Peck\Sifting algae on beach; 8 exx., JA., St. Ann Runaway Bay, 22.VIII.1974, S. Peck, beach drift; 10 exx., JA. St. Catherine, 7mi. SE. Sp. town, Hellshire Beach, 27.VII.1974, S. Peck, beach drift; 1 ex., JA., Trelawny Parish, Duncans, VIII.21.1966, Howden & Becker. Mexico: 6 exx., Mulege SEAWEED Baja Cal. Sur, Mex., J. Klink Coll., X.3.66\ERIC; Scheerpeltz; 48 exx., Sonora, NR. PT. Cirio, 29.50-112.40, 28 VIII 1974 V. Roth Coll; 163 exx., Sonora, EI Desemboque, 29.30-112.34, 23 V 1974, Brown & Speich ex flying on beach; 2♂2♀, Sonora, EI Desembogue May 23 1974 Brown & Speich; 1 ex., Veracruz Prov. 8km S Veracruz, Hwy 150, 10 July 1990 J. Ashe, K-J. Ahn, R. Leschen ex: under seaweed on beach; 1 ex., Bahia Magdelena, 1 June 1968 W. G. Evans ex; under turtle carapace\SM0038043 KUNHM-ENT. USA: 1 ex., 698., A30 S. Thomas, bistriatus Er. S. Thomas, coll. L.W. Schaufuß; 1 ex., Marion, Mass. Bowditch., Cafius bistriatus Er., Coll. Schubert; 7♂6♀ (2♂1♀ dissected, 5♂5♀ in 100% EtOH, AC220), Puerto Rico, Municipio Fajardo, Seven Seas Beach, 18°22.227'N, 65°38.359'W, 6 VI 2009, Park09-021, JS Park, ex under seaweeds; 4♂10♀ (1♂ dissected, 2♂9♀ in 100% EtOH, AC250), Florida, Pinellas Co., Anclote Gulf Park, 25 X 2008, KJ Ahn, JH Ahn, under seagrasses; 1♂5♀ (1♂ dissected, 5♀ in 100% EtOH), Florida, Brevard Co., Port Canaveral Jetty Park, 14 II 2009, KJ Ahn, under stones with empty barnacles; 2 exx., Florida Tampa, Clearwater Beach, 10 VI 1995, K.-J. Ahn., ex under seaweed; 14 exx. (2♂ dissected, 8 in 100% EtOH), Florida, Cedar Key, 28 XII 2015, KJ Ahn; 1 ex., FLA., Flamingo, Everglades Nat. Pk., 4.I.1971, L. Masner; 1 ex., CONN, Fairfield Co. Norwalk, 9 Aug 78 Calf Pasture Beach\R.E.Orth family\Wrack-debris on sandy beach; 2 exx., CONN, Fairfield Co. Westport, 11 Aug 78 Sherwood Is. St. Pk\R.E.Orth family\Wrack-debris on sandy beach\M3; 1 ex., CONN, Fairfield Co. Fairfield, 10 Aug 78 Jennings Beach\R.E.Orth family\Wrack-debris on sandy beach; 34 exx. (1♂ dissected, 33 in 100% EtOH), North Carolina, Dare Co., Oregon Inlet, 6 IV 2009, KJ Ahn, JH Ahn, under seaweeds; 2 exx., Cape Cod, Massachusetts, VII.3.1975, E. J. Kiteley, under clumps seaweed Beach; 1 ex., South Shore S. I., N. Y.\C. L. Pollard, Apr. 11-111, No.; 1 ex., Portland Maine, July 23 1966, E. J. Kiteley, dry full carcass; 1 ex., C. I.\145\Schwarz; 1 ex., Md.; 1 ex., Pt. Isabel, Texas, VI-26-30\JOMartin Collector; 2 exx., Lynn, Mass. Essex Co. V -12; 2 exx., Lynn, Mass. Essex Co.; 1 ex., N.Y. Rockaway L.I., 15.V.1941 W. Spector\C.N.H.M. 1960 Boris Malkin Coleoptera Colln.; 2 exx., Barnegat Bay NJ JW Green VIII.4.28 \C.N.H.M. 1960 Boris Malkin Coleoptera Colln.; 1 ex., Rocwy Bcb. L. L.; 1 ex., Peekskill 4/8.80 NY\Sherman; 1♀\Marion Mass. Bowditch.\Cafius bistriatus Er.\ex coll. Scheerpeltz\bistriatus Er.; 1 ex., TEXAS: Wilacy Co. Port Mansfield 30 September 1990 J. S. Ashe ex., beach wrack.
Body medium sized, length 5.5–7.7 mm, forebody length (from clypeus to end of elytron) 3.1–3.7 mm. Body brown to dark brown; head black; metaventrite dark brown to black; anterior part of epipleura usually brighter than elytra. Male. Head (Figs
Canada, USA (Pacific and Atlantic coasts), Mexico, West Indies, Venezuela.
Members of the Cafius bistriatus species complex (C. bistriatus, C. rufifrons, and C. sulcicollis) are very similar in external form and internal structure and so they could be treated as cryptic species. A comparison table of morphological characters among C. bistriatus, C. rufifrons, and C. sulcicollis is presented in Table
Cafius bistriatus A male tergite VIII, dorsal aspect B male sternite VIII, ventral aspect C male sternite IX, ventral aspect D male lateroteral sclerite and tergite X, dorsal aspect E female sternite VIII, ventral aspect F gonocoxite, ventral aspect G female tergite X, dorsal aspect H aedeagus, dorsal aspect I aedeagus, lateral aspect. Scale bar: 0.1 mm.
The diagnostic characters among members of the Cafius bistriatus species complex (C. bistriatus, C. rufifrons, and C. sulcicollis) include sculpture and punctation patterns on the head and pronotum, and form and structure of the male genitalia.
We have studied all of these species (Fig.
Comparison of morphological characters among Cafius bistriatus, C. rufifrons, and C. sulcicollis. See Fig.
C. bistriatus | C. rufifrons | C. sulcicollis | |
---|---|---|---|
Head color | black or almost black | reddish brown | black |
Head sculpture on median region | reticulate, meshes with flat cells | slightly reticulate, broken meshes | heavily reticulate, meshes with convex cells |
Median impunctate region on head | moderate in size | broader | narrower |
Pronotum sculpture on median region | slightly reticulate | glossy | dull and reticulate |
Median lobe on dorsal aspect | broader | narrower | broader |
Paramere | shorter, stout narrower than median lobe | intermediate, stout, as wide as median lobe | longer, slender, much narrower than median lobe |
Distribution | both Atlantic and Pacific coasts of North America | southern Florida-USA, Cuba | California-USA |
In addition, we used the criteria of genetic divergence and gene tree monophyly for correct identification and species delimitation of these three Cafius species. Intraspecific genetic divergence of COI using uncorrected p-distance among individuals of Cafius bistriatus ranged from 0% to 1.56%, while interspecific divergence among three species ranged from 4.90% to 14.59% (Table
Cafius bistriatus occurs on both Atlantic and Pacific coasts of North America and its dispersal depends on sea currents and winds as in C. algarum (Sharp) (
Unfortunately, only two individuals of C. rufifrons for COI and 28S sequences were available in this study, and no individuals were available for the Pacific population of C. bistriatus. For a more robust test of species limits within the C. bistriatus complex, we suggest future work to include more intensive and broader sampling from the oceanic beaches along the eastern Pacific and western Atlantic coasts.
We thank A. F. Newton and M. K. Thayer (