Eurycercus longirostris Hann, 1982 , p. 587
Elías-Gutiérrez et al. 1997 , p. 65
Bekker et al. 2010 , p. 2501
Eurycercus vernalis Hann, 1982 , p. 595
A revision of the subgenus Eurycercus (Eurycercus) Baird, 1843 emend. nov. (Cladocera: Eurycercidae) in the Holarctic with the description of a new species from Alaska
Bekker, Eugeniya I.
Kotov, Alexey A.
Taylor, Derek J.
Zootaxa
2012
2012-02-24
3206
1
1
40
3D3K6
Hann, 1982
Hann
1982
[151,586,1837,1863]
Branchiopoda
Eurycercidae
Eurycercus
Animalia
Diplostraca
18
19
Arthropoda
species
longirostris
Figs 6–7
Eurycercus longirostris Hann, 1982, p. 587–595, Figs 1–25; Elías-Gutiérrez et al.1997, p. 65, 67–68, Figs. 9–13; Bekker et al.2010, p. 2501, Fig. 12. Eurycercus vernalis Hann, 1982, p. 595–596.
Type locality."Big TurkeyLake, Lagrange Co" ( Hann 1982), Indiana, U.S.A.Approximate geographic coordinates: 41.59, -85.19. Holotype.A parthenogenetic female, 1.44 mm, in alcohol, USNM 181893. Paratypes.A parthenogenetic female on a slide in glycerine jelly, USNM 181895. Two parthenogenetic females in alcohol, and one parthenogenetic female in glycerine jelly on a slide, NHM 1980.371, 1980.372. A parthenogenetic female in alcohol, and one parthenogenetic female in glycerine jelly on a slide, CMNC-1981-217. An ephippial female in glycerine jelly, USNM 181896. “In addition, one exuviamounted in polyvinyl lactophenol on a slide has been deposited in each of the three museums listed above. All other specimens are in the author's collection” ( Hann 1982). Allotype.A mature male in glycerine jelly, USNM 181894. Material examined here: Canada. British Columbia. MoreiLake, coll. in 02.07.2005by M. Belyaeva& S. Ishida, DJT 3-618( 59.955, -132.024). Manitoba. Fish House Pond, Boatdoek at Delta Marsh Field Station, coll. in 19.09.1982by M. M. Boucherle, DGF 6770(49.97, -98.29); Weir Channel, Churchill, coll. in 16.08.2006by M. Eíias-Gutiérrez, AAK M-0898 and AAK M-0891 ( 58.672, -94.161). Newfoundland and Labrador. Ocean Pond, coll. in 03.07.2005by L.J. Hovind& M. Faustova, AAK M-0487 ( 47.4442, -53.4118). Nova Scotia.A lake, west side of Hgy.349, 0.5 milesN of Williamswood/ Harrietsfieldboundary, coll. in 31.10.1984by D. G. Frey, DGF 7328(44.55, -63.64). Ontario.Pond 3 milesE Manitoba/ Ontarioborder, on Trans-Canada Hwy, coll. in 29.08.1974by D. G. Frey, DGF 3660(49.73, -95.11); Pond on Opeongo Road, Algonquin Park, coll. in 08.10.1982by S & F, DGF 6446(45.56, -78.6); Sydenham Lake, Sydenham, coll. in 11.10.1982by S & F, DGF 6490( 44.4226, - 76.5559). Yukon. SquangaLake, coll in 02.07.2005by M. Belyaeva& S. Ishida, DJT 3-624, DJT 3-625and AAK M-0477 ( 60.4478, -133.603). U.S.A. Alaska. Birch Lale, Anchorage, coll. 8.08.2011by D. J. Taylor, A. A. Kotov, M. Ballinger& A. Medeiros, DJT20_2011_ Ancourage_04 ( 61,14558, -149,9384). California.CPR Pond2, coll. in 01.05.2001by E. Gallo, AAK 2007-319; Lower Twin Lakein Robinson, Creek Valley, coll. in 12.09.1965by D. G. Frey, DGF 1726( 40.5066, -121.3639). Colorado. Ponded Brookletnear Upper Red Rock Lake, coll. in 02.09.1975by D. G. Frey, DGF 1704( 40.0816, -105.5412). Connecticut. BeachPond, coll. in 14.06.2004by D. J. Taylor& A. A. Kotov, AAK 2005-234( 41.5837, -71.7222). Indiana. HammondLake, coll. in 29.10.2006by S. Ishida& K. Kim, AAK M-1124 ( 41.3647, -85.6775); OliverLake, coll. in 25.11.1966by D. G. Frey, DGF 2342( 41.5724, -85.4051); Silver Lake, coll. in 29.10.2006by S. Ishida & K. Kim, AAK M-1128 (41.08, -85.9). Maine. Meddybemps Lake, Hgy.119, Moosehorn Wildlife Refuge, coll. in 09.11.1984by G. Frey, DGF 7346(45.07, -67.37); SebagoLake, coll. in 11.08.1966by D. G. Freyand 09.1981 by D. B. Berner, DGF 1911, DGF 1874and AAK 1999-103 ( 43.778, - 70.518). Massachusetts. Pequot Pond, coll. in 26.06.2004by A. A. Kotov& W. Piel, AAK M-0076 (42.18, - 72.692). Michigan. Douglas Lake, MarlBay, coll. in 29.07.1961by D. G. Frey, DGF 0295(45.58, -84.69); HamiltonLake, coll. in 07.07.1966by D. G. Frey, DGF 1857( 45.7551, -87.7854); TwinLake, coll. in 31.01.1975by D. G. Frey, DGF 0303( 43.3676, -86.1716). Minnesota. Newton Lakein BWCA near Ely, coll. in 08.08.1979by D. G. Frey, DGF 5250( 47.9768, -91.7273). Mississippi. Pearl RiverSystem, Chien's Sta. 3, 1.2 milesSW of jct. 411 on State Road12 near McCool, coll. in 09.05.1974by D. G. Frey, DGF 3413(33.21; -89.36); Roadsideditch, Hwy39W, ca. 4 milesS of Indianola , coll. in 13.03.1978by D. G. Frey, DGF 4583(33.5, -90.6). New Hampshire. Otter Pondnear SunapeeLake, coll. in 24.06.2004by W. Pill& A. A. Kotov, AAK 2005-255( 43.4303, -72.0587); Sunapee Lakeat Brich Point, coll. in 24.06.2004by W. Piel& A. A. Kotov, AAK 2005-264- 265(43.3756, -72.07). New York. Fishpondnear Atlanticcity Reservoir, coll. in 01.05.1995by H. Segers, AAK 1998-014(39.44, -74.55); Lake Erie, coll. in 25.06.2006by L. Hovind, AAK M-0272 ( 42.8503, -78.8742); Pond3, Brigantine National Wildlife Refuge, coll. in 08.05.1995by H. Segers, AAK 1998-016(39.4, -74.4); Round Pond, Long Island, coll. in 12.06.2004by D. J. Taylor& A. A. Kotov, AAK 2005-223( 40.9857, -72.2914). North Carolina. Lake Carolina, coll. in 07.06.2005by L.J. Hovind, DJT 20-129( 35.475, -79.075); PagesLake, coll. in 18.08.1958by P. Patterson, DGF 0050( 35.1379, -79.4304); Panther Lake, 02.03.1979by D. G. Frey, DGF 3759( 35.5678, -78.6955). Pennsylvania. Swingle Road Pond, coll. in 11.06.2004by D. J. Taylor& A. A. Kotov, DJT 20-004( 41.4154, -75.3162); Swingle Road Pond, coll. in 06.2004 by D. J. Taylor& A. A. Kotov, AAK 2005-219( 41.4154, -75.3162). Rhode Island. Bowdish Reservoir, coll. in 14.06.2004by D. J. Taylor& A. A. Kotov, AAK 2005-236and DJT 20-037 ( 41.9242, -71.7826). Tennessee. Poolbetween road and Reelfoot Lake, 1 mileN of Dods, Tennessie Nat. Wildlife Ref. , coll. in 11.10.1974by D. G. Frey, DGF 3427(36.4, -89.4). Vermont. CrystalLake, coll. in 26.03.1975by D. G. Frey, DGF 2600( 44.7338, -72.1539). Washington. Green Lake, Seattle, coll. in 22.10.1983by D. G. Frey, DGF 6695( 47.6784, -122.3381); Slough, upper end of Lake Quinault, Rain Forest Camp, Olympic Peninsula, coll. in 27.06.1978by D. G. Frey, DGF 4895(47.49, -123.85). Wisconsin. FoxLake, coll. in 23.06.1956by D. G. Frey, DGF 0248( 43.5822, -88.919). Mexico. State of Mexico. Lake La Luna, in the crater of the volcano Nevadode Toluca, coll. in 04.06.1994by M. Elías-Gutiérrez, AAK 2002-106 ( 19.1036, -99.7556).
Diagnosis.Parthenogenetic female.Dorsal head pores on a bubble-like projection located immediately on head shield. In anterior view, body wide, not compressed laterally, median dorsal keel absent. Rostrum relatively long. Ocellus of moderate size. Lateral head pore circular. Labrum with a moderate median keel, with broadly rounded apex, reaching distal end of antenna I length. Postabdomen with sub-parallel dorsal and ventral margins, preanal teeth pointed. Spines at base of pre-claw portion predominantly single. Antenna I with antennular sensory seta arising somewhat basally to middle. Denticles in rows encircling antennular surface relatively large. On antenna II, spine situated on proximal segment of exopod equal to or somewhat shorter than second segment. Limb I IDL with a strong hook-like seta, the smallest IDL seta especially fine and short. IDL with about 4–11 distal spinules, 3–15 proximal spinules, 1–11 marginal spinules and 0–12 basal spinules. Eight setae in filter plate II, 9 setae in filter plate III; 9 setae in filter plate IV, 8 setae in filter plate V. Short redescription.Parthenogenetic female.In lateral view body sub-ovoid in larger females ( Fig. 6A), maximum height of the body in its middle portion (BH/BL= 0.57–0.59). Dorsal margin interrupted only by a bubble-like head pore. In anterior view, body wide, not compressed laterally, maximum width of body at level of mandibular articulation. Median dorsal keel is absent. A single midgut loop, posterior intestinal caecum present. Few eggs in the brood pouch. Headlarge, with well expressed, relatively long rostrum ( Fig. 6B). The anterior portion of headshield (= portion anterior to level of mandibular articulation) more than two times lager than posterior one, broadly rounded, with slightly projected rostral region ( Fig. 6C). A single major “head pore” as a ringed, sub-oval field of special cuticle located on a dorsal bubble. A small, circular lateral pore located at either side of major pore, closer to it ( Fig. 6D). Labrum fleshy body, with a medium-size median keel, terminating in a broadly rounded apex ( Fig. 6B) and with paired lateral horn-like projections ( Fig. 6E). Valvesgenerally ovoid (VL/BL= 0.78–0.87), armature of posterior valve margin as in previous species ( Fig. 6F–H). Postabdomenlarge (PL/BL= 0.41–0.44), relatively broad ( PH/PL= 0.48–0.56), with sub-parallel dorsal and ventral margins ( Fig. 6I). Distal anal embayment shallow. Armature of the preanal margin as a series of preanal teeth (NT=87–98); distalmost tip somewhat larger than others; small gap lacking any teeth at base of postabdominal setae; teeth in middle of preanal margin with sharp tips. Distalmost postanal teeth long, clustered; teeth at base of pre-claw portion mainly single ( Fig. 6J, arrows). Postabdominal setae as in previous species. Postabdominal claw relatively robust (CL/PL= 0.22–0.24); basal spines, first (distal) long (DS/CL= 0.30–0.47), second (basal) short (BS/CL= 0.13–0.22; BS/DS = 0.38–0.44). Antenna I( Fig. 6K) relatively short (AL/BL = 0.10–0.11; AL/DA=2.86–3.42), triangular in cross section; protruding beyond tip of rostrum. Antennular sensory seta relatively short (about third of antenna I length), arising basally to antenna I middle. Nine bisegmented aesthetascs, with pointed teeth around them. Numerous short rows of relatively large denticles encircling antennular surface. Antenna IIrelatively short; spine situated on proximal segment of exopod somewhat shorter than or equal to length of second segment ( Fig. 6L). Setae 0-0-3/1-1-3; spines 1-0-1/0-0-1. Thoracic limbs( Fig. 7A–L) basically similar with those in E. macracanthus, some differences described below. Limb I with IDL with a strong hook-like seta ( Fig. 7A–D), but not so large as in E. macracanthus. In contrast to the latter, the smallest seta of IDL stronger in E. longirostris. IDL with long distal spinules (4–11), long proximal spinules (3–15), short marginal spinules (1–11) and short basal spinules (0–12). On exopodite III seta 7 short, eight soft setae on inner limb portion ( Fig. 7G). On exopodite IV seta 1 relatively long ( Fig. 7I). On exopodite V setae 5–7 increasing in size distally ( Fig. 7J). Filter plate of gnathobase III, IV with 9 setae, and limb V with 8 setae. Ephippial female, male.See Hann (1982). Length.1.17–2.00 mm in our material.
Comments. Hann (1982)described two species, E. longirostrisand E. vernalis, and concluded that there are no evident morphological differences between them. Only ontogenetic changes were found to be different, as revealed by a statistical analysis of the instar variability. Unfortunately, such ontogenetic differences are difficult to interpret and diagnose. We concluded that the patterns of instar variability found by Hann (1982)lack discreteness when more populations are examined ( Bekker 2011). So, we believe that absence of any diagnostic traits of Hann's (1982)two taxa is due to their synonymy. FIGURE 6. Eurycercus longirostris, parthenogenetic female from CPR WDS, California, U.S.A. (A, C, D, F, G, H, K, L); Oliver Lake, Indiana, U.S.A. (B, E, I); Lake La Luna, in the crater of the volcano Nevado de Toluca, State of Mexico, Mexico (J). A, lateral view. B, head. C, head shield. D, head pores. E, labrum, ventral view. F, setae at anterior portion of valves. G, setae at postero-ventral portion of valve. H, armature of valve posterior margin. I, postabdomen. J, its distal portion. K, antenna I. L, antenna II. Scale bar denotes 1 mm (A); 0.1 mm (B-I). FIGURE 7. Eurycercus longirostris, limbs of parthenogenetic female from CPR WDS, California, USA (A–C, E–K); Lake La Luna, in the crater of the volcano Nevado de Toluca, State of Mexico, Mexico (D, L). A, limb I. B, its distal portion. C–D, inner distal lobe. E, limb II. F, distal armature of its gnathobase. G, limb III. H, its inner-distal portion. I, limb IV. J, limb V. K, distal armature of its gnathobase. L, limb VI. Scale bar denotes 0.1 mm. We found a small divergence of COIsequences among populations from distant points of the USA, including Indiana(the typelocality of E. longirostris) and North Carolina(the typelocality of E. vernalis). We found a separate sub-clade in Rhode Islandand Newfoundland, but its separation from E. longirostriscould not be associated with Hann's (1982)separation of E. longirostrisand E. vernalis. Note that the opinion of Hann (1982)is influenced by Frey's (1982b)idea that populations of cladocerans in southern and northern regions of North America become reproductively isolated as their timing of gamogenesis diverges (in autumn in the North and in spring in the South), which leads to speciation. It is presently unclear if there are good examples of this mode of speciation in cladocera. Geographic clades are commonly found in cladocerans, but these are often West-East, not South-North ( Taylor et al.1998). For genetically differentiated northsouth species, it is unclear if differences in the timing of reproduction are a cause or an effect of speciation (Constanzo & Taylor 2010). Case 24.2.1 of ICZN (2000) proposed that "When the precedence between names or nomenclatural acts cannot be objectively determined, the precedence is fixed by the action of the first author citing in a published work those names or acts and selecting from them; this author is termed the "First Reviser"”. We followed this code, and Eurycercus vernalis Hann, 1982is found by us to be a junior synonym of E. longirostris Hann, 1982.
Distribution.It is a remarkable fact that the southernmost populations of E. longirostrisoccur in Central Mexico ( Elías-Gutiérrez et al.1997, 2008) which is the southernmost portion of the Nearctic, while in nearby Neotropical Mexico, Belizeand Guatemala( Elías-Gutiérrez et al.2006, 2008), Central America and the West Indies ( Frey 1982a) E. longirostrisis almost certainly absent. There is a big gap in the distribution of Eurycercussouth to Central Mexico until Columbia (see Aranguren et al.2010; Bekker et al.2010). So, the taxa of Eurycercusmight be subdivided into the Nearctic and the Neotropical. We know that E. longirostris s.str.is widely distributed through whole U.S.A.and southern Canada( Hann & Karrow 1984; Chengalath 1987; Lemke & Benke 2004) and present even in Churchill ( Manitoba, Canada) ( Jeffery 2011) and the YukonTerritories (our data). But more Canadian populations need to be studied to further assess species diversity. At least, the molecular data suggests a more complicated situation (see two clades in the COIchapter in this article).
Ecology.It is widely distributed in water bodies of different types. We found that two "species" according to Hann (1982)appear to belong to a sole taxon. The range of thermal preferences of E. longirostrisis quite wide as evidenced by a record from subarctic Churchill.
CMN
19
20
USNM 181895, NHM 1980.371, 1980.372, USNM 181896
1
1
paratype
[201,870,475,500]
USNM
19
20
USNM 181894
1
allotype
2005-02-07
DJT
Morei & M. Belyaeva & S. Ishida
Canada
59.955
British Columbia
62
-132.024
19
20
DJT 3-618
1
British Columbia
1982-09-19
2006-08-16
1982-09-19
DGF
M. M. Boucherle & Weir Channel & Churchill & Eiias-Gutierrez
Canada
Fish House Pond
58.672
Delta Marsh Field Station
62
-94.161
Boat
19
20
DGF 6770
1
Manitoba
2005-03-07
Ocean Pond & L. J. Hovind & M. Faustova
Canada
47.4442
Newfoundland and Labrador
6
-53.4118
19
20
1
Newfoundland and Labrador
1984-10-31
DGF
D. G. Frey
Canada
Harrietsfield
Hgy.
19
20
DGF 7328
1
Nova Scotia
[394,778,727,752]
Canada
3 miles E Manitoba
19
20
1
Ontario
1974-08-29
1982-11-10
1974-08-29
DGF
Trans-Canada Hwy & D. G. Frey & Algonquin Park
Canada
Pond on Opeongo Road
44.4226
Sydenham
6
-76.5559
Sydenham Lake
19
20
DGF 3660, DGF 6446, DGF 6490
1
Ontario
2005-02-07
DJT
Squanga & M. Belyaeva & S. Ishida
Canada
60.4478
Yukon
27
-133.603
19
20
DJT 3-624, DJT 3-625
1
Yukon
2011-08-08
DJT
Anchorage & D. J. Taylor & A. A. Kotov & M. Ballinger & Medeiros & Ancourage
United States of America
61.14558
Birch Lale
2
-149.9384
19
20
DJT20
1
Alaska
2001-01-05
AAK
E. Gallo
United States of America
Lower Twin Lake
Pond
19
20
AAK 2007-319
1
California
1965-12-09
DGF
Creek Valley & Frey
United States of America
40.5066
6
-121.3639
19
20
DGF 1726
1
California
[405,774,1015,1040]
Ponded Brooklet
United States of America
Colorado
19
20
1
Colorado
1975-02-09
DGF
Frey
United States of America
40.0816
6
-105.5412
19
20
DGF 1704
1
Colorado
2004-06-14
AAK
Beach & D. J. Taylor & A. A. Kotov
United States of America
41.5837
Connecticut
6
-71.7222
19
20
AAK 2005-234
1
Connecticut
2006-10-29
Hammond & S. Ishida & K. Kim
United States of America
41.3647
Indiana
6
-85.6775
19
20
1
Indiana
[484,1358,1124,1148]
1966-11-25
DGF
Oliver & Frey
United States of America
41.5724
6
-85.4051
19
20
DGF 2342
1
Indiana
Hgy.
United States of America
Meddybemps Lake
19
20
1
Maine
[206,1185,1196,1220]
1984-09-11
DGF
Moosehorn Wildlife Refuge & Frey
United States of America
19
20
DGF 7346
1
Maine
1966-11-08
DGF
Sebago & D. G. Frey & Berner
United States of America
43.778
68
-70.518
19
20
DGF 1911, DGF 1874
1
Maine
2004-06-26
Pequot Pond & A. A. Kotov & W. Piel
United States of America
Massachusetts
19
20
1
Massachusetts
[251,1344,1304,1328]
1961-07-29
DGF
Marl & D. G. Frey
United States of America
Douglas Lake
19
20
DGF 0295
1
Michigan
1966-07-07
DGF
Hamilton & Frey
United States of America
45.7551
6
-87.7854
19
20
DGF 1857
1
Michigan
1975-01-31
DGF
Twin & Frey
United States of America
43.3676
6
-86.1716
19
20
DGF 0303
1
Michigan
[609,1067,1376,1400]
United States of America
Newton Lake
19
20
1
Minnesota
1979-08-08
DGF
Ely & Frey
United States of America
47.9768
6
-91.7273
19
20
DGF 5250
1
Minnesota
State Road
United States of America
Pearl River
19
20
1
Mississippi
1974-09-05
DGF
McCool & D. G. Frey & Roadside & Hwy
United States of America
4 miles S of Indianola
19
20
DGF 3413
1
Mississippi
[507,1172,1484,1508]
1978-03-13
DGF
Frey
United States of America
19
20
DGF 4583
1
Mississippi
Otter Pond
United States of America
New Hampshire
19
20
1
New Hampshire
[278,1432,1520,1544]
2004-06-24
AAK
Sunapee & Pill & A. A. Kotov
United States of America
43.4303
6
-72.0587
19
20
AAK 2005-255
1
New Hampshire
[151,336,1556,1580]
United States of America
Sunapee Lake
19
20
1
New Hampshire
[343,1432,1556,1580]
2004-06-24
AAK
Brich Point & Piel & A. A. Kotov
United States of America
19
20
AAK 2005-264, 265
1
New Hampshire
[151,576,1592,1616]
Fishpond & Atlantic
United States of America
New York
19
20
1
New York
[583,1431,1592,1616]
1995-01-05
AAK
Reservoir & Segers
United States of America
19
20
AAK 1998-014
1
New York
[1053,1131,1628,1652]
United States of America
Pond
19
20
1
New York
1995-08-05
AAK
Brigantine National Wildlife Refuge & H. Segers & Round Pond
United States of America
19
20
AAK 1998-016
1
New York
2004-12-06
AAK
D. J. Taylor & A. A. Kotov
United States of America
40.9857
Long Island
6
-72.2914
19
20
AAK 2005-223
1
Long Island
2005-07-06
DJT
Lake Carolina & L. J. Hovind
United States of America
35.475
North Carolina
71
-79.075
19
20
DJT 20-129
1
North Carolina
1958-08-18
DGF
Pages & Patterson
United States of America
35.1379
6
-79.4304
19
20
DGF 0050
1
Lake Carolina
[515,1327,1772,1796]
1979-02-03
DGF
D. G. Frey
United States of America
35.5678
Panther Lake
6
-78.6955
19
20
DGF 3759
1
Lake Carolina
2004-11-06
DJT
Swingle Road Pond & D. J. Taylor & A. A. Kotov
United States of America
41.4154
Pennsylvania
6
-75.3162
19
20
DJT 20-004
1
Pennsylvania
[151,1353,1844,1868]
AAK
Swingle Road Pond & D. J. Taylor & Kotov
United States of America
41.4154
6
-75.3162
19
20
AAK 2005-219
1
Pennsylvania
2004-06-14
AAK
Bowdish Reservoir & D. J. Taylor & A. A. Kotov
United States of America
41.9242
Rhode Island
6
-71.7826
19
20
AAK 2005-236
1
Rhode Island
United States of America
Pool
Tennessie Nat. Wildlife Ref.
Reelfoot Lake
19
20
1
Tennessee
[201,855,1952,1977]
1974-11-10
DGF
Frey
United States of America
19
20
DGF 3427
1
Tennessee
1975-03-26
DGF
Crystal & D. G. Frey
United States of America
44.7338
Vermont
6
-72.1539
19
20
DGF 2600
1
Vermont
1983-10-22
DGF
Seattle & D. G. Frey
United States of America
20
21
47.6784
Green Lake
6
-122.3381
19
20
DGF 6695
1
Washington
[472,713,151,175]
United States of America
Slough
20
21
1
Washington
1978-06-27
DGF
Camp & Olympic Peninsula & D. G. Frey
United States of America
Rain Forest
Lake Quinault
20
21
DGF 4895
1
Washington
1956-06-23
DGF
Fox & D. G. Frey
United States of America
43.5822
Wisconsin
40
-88.919
20
21
DGF 0248
1
Wisconsin
1994-04-06
Nevado & M. Elias-Gutierrez
Mexico
19.1036
Lake La Luna
7
-99.7556
Nevado de Toluca
20
21
1