Entocythere cambaria Marshall, 1903

Williams, Bronwyn W. & Weaver, Patricia G., 2019, Redescription and Clarification of Type Designation of Entocythere cambaria Marshall, 1903 (Ostracoda: Entocytheridae) and synonymization of Entocythere illinoisensis Hoff, 1942, Zootaxa 4565 (2), pp. 261-273 : 263-269

Entocythere cambaria Marshall, 1903

Figures 1–4 .

Entocythere cambaria Marshall, 1903

Entocythere (Entocythere) cambaria Marshall, 1903

Entocythere (Entocythere) illinoisensis Hoff, 1942

Entocythere illinoisensis Hoff, 1942

Emended Diagnosis. Carapace subovate to semi-elliptical with eye located near anterodorsal margin. Adults with well-developed respiratory plate and masticatory lobes; mandible with six multi-cuspid, but not pectinate teeth, terminal tooth larger than preceding teeth; antennule consisting of six podomeres; antennae consisting of four podomeres, posterior surface of dorsal apical antennal claw of male setiferous, antennal claws of adult female triunguis, ventral claw with pectinate prominences on either side of base. Legs with terminal claws. Peniferum of adult male short, not extending beyond midpoint of clasping apparatus, without accessory groove or finger guard, distal end of peniferum blunt, sclerotized, with ventrally directed tooth-like process on anterodistal face. Penis medium sized, sub-ovate, situated within distal ¼ of peniferum. Clasping apparatus L-shaped with 5 teeth and 3 denticles. Genital complex of female intricate coil embedded in amorphous mass with 1 ventrally directed acute projection.

Type locality. Original description from specimens collected from streams near Madison, Dane County, Wisconsin, U.S.A. and other unspecified localities in the state. Neotype designated by Hart & Hart (1974) from Yahara River near Sun Prairie where river crosses Route 19 near Madison , Dane County, Wisconsin.

Description. ADULT MALE (neotype USNM 1462653).—Carapace subovate to semi-elliptical, cracked in several places ( Fig. 2A, B ). Length 540 µm and height 295 µm. Spinneret gland present, situated posterior to eye.

Antennule consisting of six podomeres ( Fig. 3A ); first, i.e., most proximal, podomere with one seta on posterolateral margin; second podomere with one seta originating from distolateral margin and extending at least the length of third podomere; third podomere with two setae, one each on anterolateral and posterolateral margins, anterolateral seta extends just beyond fourth podomere, posterolateral seta slightly longer, extending to mid-length of fifth podomere; fourth podomere with three anterolateral setae, variable in length, ranging from just beyond fifth podomere to just beyond mid-length of sixth podomere, two posterolateral setae, approximately equal in length extending nearly to distal end of sixth podomere; fifth podomere without visible setae; sixth podomere terminating in a cluster of five setae. The other antennule broken at second podomere.

Antenna consisting of four podomeres ( Fig. 3B ); first podomere with long, unjointed exopodite extending from distolateral margin to beyond terminal claws; second podomere with one seta extending from posterolateral margin; third podomere with one seta extending from posterolateral margin; fourth podomere with one seta on posterolateral surface originating at mid-length, bearing three terminal claws; dorsal claw with setae on distal third and notch on posterior surface proximal to setae; mesial claw short with setae visible on posterior surface; ventral claw with discernable short setae.

Mandibular palp elongate, with two podomeres of unequal length. Distal end of main part of elongate podomere with long sub-apical seta and shorter apical seta on outer edge, and long, distally bent seta along inner edge. Terminal mandibular podomere sub-quadrate with terminal talon-shaped projection and two apical setae. Three long backswept setae (sensu Smith & Kamiya 2001) of branchial plate of palp discernable, extending proximally from mid-dorsal portion of palp. Mandibular coxa with well developed endite with six mandibular teeth with distal tooth larger than preceding teeth, all multi-cuspid but not pectinate ( Fig. 3C ). Rake-shaped organ (labial plate sensu Hart & Hart 1974) broad at distal end with approximately 11 lobes ( Fig. 3D ).

Maxillula consists of palp, masticatory lobe and branchial plate (respiratory lobe sensu Hart & Hart 1974) ( Fig. 3E ). Palp elongate without segmentation, terminating in two setae. Masticatory lobe terminating in two shorter setae. Branchial plate semi-circular with multiple setae radiating outward along its outer edge.

Fifth limb with four podomeres ( Fig 3F ), first podomere broad and trapezoidal (broader proximally than distally) with one long seta and one short seta extending from distal anterior margin, also with three evenly spaced setules along anterior margin. Second podomere elongate, with one small seta on sub-distal anterior margin, also with three evenly spaced setules along anterior margin. Third podomere short and sub-rectangular with one hirsute seta extending from distal anterior margin, also with two setules on posterior margin. Fourth podomere quadrate, without setae. Distal end of fourth podomere bearing a hook-like claw with five partitions, only three visible.

Sixth limb with four podomeres ( Fig. 3G ), first podomere broad and trapezoidal (broader proximally than distally) with one long seta extending from distal anterior margin, also with four evenly spaced setules along anterior margin. Second podomere elongate, slightly broader distally than proximally, with one short seta extending from sub-distal anterior margin, also with four evenly spaced setules along anterior margin. Third podomere sub-rectangular, with one hirsute seta extending from distal anterior margin, also with one setule on anterior margin in distal ½ and two setules on posterior margin. Fourth podomere quadrate, with two short setae on anterior margin. Distal end of fourth podomere bearing hook-like claw with five partitions.

Seventh limb with four podomeres ( Fig. 3H ), first podomere elongate, broader proximally than distally, with one long seta extending from distal anterior margin, also with four evenly spaced setules along anterior margin. Second podomere elongate, slightly broader distally than proximally, with one short seta on sub-distal anterior margin, also with four evenly spaced setules along anterior margin. Third podomere sub-rectangular with one hirsute seta extending from distal anterior margin, also with one setule on anterior margin in distal ½ and two setules on posterior margin. Fourth podomere quadrate with two short setae on posterior margin. Distal end of fourth podomere bearing hook-like claw with five partitions, two partitions obscured by angle of claw.

Copulatory complex of male ( Fig. 2C, D ): peniferum short not extending beyond midpoint of clasping apparatus terminating bluntly, extreme distal margin strongly sclerotized, with ventrally directed tooth-like process on anterodistal face, without accessory groove or finger guard; penis, medium sized, sub-ovate, situated within distal ¼ of peniferum; clasping apparatus entire L-shaped, vertical and horizontal rami approximately equal in length, external margin of vertical ramus concave giving distal end a heel-like appearance, internal margin of vertical ramus with slight shoulder on anterodistal surface above junction with horizontal ramus, horizontal ramus with five teeth and three denticles; dorsal finger broad proximally, tapering distally, terminating in a medium sized spine; ventral finger long, slender, approximately twice the length of dorsal finger, terminating in medium sized spine.

ADULT FEMALE [description based on USNM 1462654, previously uncatalogued, from stream about 10 miles east of Tahlequah, Cherokee County, Oklahoma; host Faxonius neglectus neglectus ( Faxon, 1885) ].— Carapace sub-ovate broader posteriorly than anteriorly, bearing damaged egg sac; ventral margin with slight concavity ( Fig. 4A, B ). Length 618 µm and height 335 µm.

Antennule as per male. Antenna of adult female differs from that of adult male. Antenna consisting of four podomeres ( Fig. 4C ); first podomere with long, unjointed exopodite extending from distolateral margin to beyond terminal claws; second podomere with one seta extending from posterolateral margin; third podomere with two setae of unequal length extending from posterolateral margin; fourth podomere with one seta on posterolateral surface originating at mid-length. Fourth podomere bearing three terminal claws, dorsal claw with setae on posterior surface; mesial claw short with setae visible on posterior surface; ventral claw with claw-like projections and pectinate prominences on either side of base, with six to seven partitions on one side, and approximately nine partitions on the other side ( Fig. 4C, D ).

Mandible and maxillula as per male. Fifth limb with four podomeres ( Fig. 4E ), first podomere broad and trapezoidal (broader proximally than distally) with two long hirsute setae extending from distal anterior margin, also with three evenly spaced setules along anterior margin. Second podomere elongate, with one small seta on sub-distal anterior margin, also with three evenly spaced setules along anterior margin. Third podomere short and sub-rectangular with one hirsute seta extending from distal anterior margin. Fourth podomere quadrate, without setae. Distal end of fourth podomere bearing a hook-like claw with five partitions. Sixth and seventh limbs as per male.

Genital complex composed of complex coil embedded in amorphous mass with one ventrally directed acute projection ( Fig. 4F, G ).

Additional Material Examined. We examined several additional previously uncatalogued lots in the USNM IZ Collection that had been identified as E. cambaria , E. illinoisensis , or E. sp. ( Fig. 1 ). This material, now catalogued, includes USNM 1462655, 1462656, and 1460561 (Cherokee County, Oklahoma), USNM 1460577 (Le Flore County, Oklahoma), USNM 1460569 (Independence County, Arkansas), USNM 1460575 (Montgomery County, Arkansas), USNM 1460574 (Randolph County, Arkansas), USNM 1460573 (Saline County, Arkansas), USNM 1460570 (Yell County, Arkansas), and USNM 1462658 (Oconto County, Wisconsin).

Variations. Adult carapace ranges in length between 448 and 595 µm (males) and 468 and 709 µm (females), and height between 245 and 344 µm (males) and 266 and 392 µm (females). Although consistent across most specimens examined, the setules on the 5th–7th limbs may vary in number in some individuals. The external margin of the horizontal ramus ranges from linear, or straight, to sinuous, and the appearance of the “heel” of the clasping apparatus, i.e., the external junction of the horizontal and vertical rami, ranges from sharply acute to rounded (e.g., Fig. 2D . 1 , D. 2 , E. 1, F.1 ). The distal end of the peniferum varies in appearance and shape, specifically the degree to which it appears strongly sclerotized, and the presence, or seemingly absence, of a ventrally directed tooth-like process on anterodistal face. The spine of the dorsal finger is clearly bifid in some specimens and seemingly not bifid in others (e.g., Fig. 2D, E, F ). All of the above perceived variations may be a result of the angle of the specimen on the slide.

The number of visible pectinate prominences on the base of the ventral claw of the antenna in adult females varies, but seems to be a minimum of seven each side. In some individuals the genital complex appears to lack the coil structure, but in these cases it is likely obscured by the dense amorphous material surrounding the organ. The genital complex as a whole, when visible, was consistent across all examined specimens.

Distribution. Marshall (1903) reported E. cambaria from streams near Madison, Wisconsin, USA and additional unspecified locations elsewhere in the state, the latter based on crayfishes procured from a dealer. Entocythere cambaria occupies a broad range across the central USA, from northern Alabama and Mississippi north to Michigan and Wisconsin, and from eastern Oklahoma east to Ohio and western Virginia ( Hart & Hart 1974). Localities in Fig. 1 are compiled from published records and newly examined specimens in the USNM IZ Collection for both E. cambaria and E. illinoisensis , the latter now deemed a junior synonym of the former.

Hosts. According to Marshall (1903), E. cambaria occurred on different species of “ Cambarus .” Given the area and habitat from which these crayfishes were collected, it is likely that the species from which Marshall recovered E. cambaria were one or more of the following: Faxonius immunis ( Hagen, 1870) , F. propinquus , Faxonius virilis ( Hagen, 1870) and/or Procambarus acutus ( Girard, 1852) . The neotype was recovered from F. propinquus [formerly Orconectes propinquus , mistakenly reported as Cambarus propinquus by Hart & Hart (1974)]. Other hosts from which E. cambaria has been reported include Cambarus bartonii bartonii ( Fabricius, 1798) , Cambarus extraneus Hagen, 1870 , Cambarus girardianus Faxon, 1884 , Cambarus graysoni Faxon, 1914 , Cambarus laevis (= C. tenebrosus Hay, 1902 ), Cambarus longirostris Faxon, 1885 ), Cambarus parvoculus Hobbs & Shoup, 1947 , Cambarus ornatus (= Cambarus tenebrosus ), Cambarus sphenoides Hobbs, 1968 , Cambarus striatus Hay, 1902 , Cambarus (Depressicambarus) sp., Cambarus (Jugicambarus) sp., Cambarus sp., Faxonius acares ( Fitzpatrick, 1965) , Faxonius alabamensis ( Faxon, 1884) , Faxonius compressus ( Faxon, 1884) , Faxonius difficilis ( Faxon, 1898) , Faxonius erichsonianus ( Faxon, 1898) , Faxonius forceps Faxon, 1884 ), Faxonius hylas ( Faxon, 1890) , Faxonius juvenilis ( Hagen, 1870) , Faxonius longidigitus ( Faxon, 1898) , Faxonius medius ( Faxon, 1884) , Faxonius meeki ( Faxon, 1898) , Faxonius meeki brevis ( Williams, 1952) , Faxonius nana ( Williams, 1952) , F. n. neglectus , Faxonius ozarkae ( Williams, 1952) , Faxonius palmeri longimanus ( Faxon, 1898) , Faxonius placidus ( Hagen, 1870) , Faxonius punctimanus ( Creaser, 1933) , Faxonius putnami ( Faxon, 1884) , Faxonius quadruncus ( Creaser, 1933) , Faxonius rusticus ( Girard, 1852) , Faxonius spinosus ( Bundy, 1877) , Faxonius sp., Procambarus elegans Hobbs, 1969 , Procambarus sp. nr. Procambarus gracilis (Bundy in Forbes, 1876) , Procambarus (O.) lophotus Hobbs & Walton, 1960a, and Procambarus tenuis [= Fallicambarus tenuis ( Hobbs, 1950) ]. Crayfish names have been modified from original records to reflect current accepted nomenclature, but not necessarily taxonomic activity that has occurred since. Specific localities for these host associations can be found in Hart & Hart (1974) and the USNM IZ Collections online database.

Entocytherid associates. Known associates include Thermastrocythere riojai ( Hoff, 1943) , Uncinocythere simondsi ( Hobbs & Walton, 1960b) , Dactylocythere mecoscapha ( Hobbs & Walton, 1960b) , Dactylocythere astraphes Hobbs & Walton, 1977 , Dactylocythere falcata ( Hobbs & Walton, 1961) , Dactylocythere xystroides Hobbs & Walton, 1963b , Donnaldsoncythere donnaldsonensis ( Klie, 1931) , Entocythere elliptica Hoff, 1944 , Ankylocythere copiosa ( Hoff, 1942) , Ankylocythere hyba Hobbs & Walton, 1963b , and Ankylocythere sinuosa ( Rioja, 1942) . Specific localities and hosts corresponding to these associations can be found in Hart & Hart (1974) and on the USNM IZ Collections online database.

Figures

FIGURE 1. Map of the known distribution of Entocythere cambaria based on published records (as compiled in Hart & Hart 1974) and previously uncatalogued specimens in the USNM IZ Collection (denoted by an asterisk, *). Shading of circles is based on identification prior to this study: dark grey represents E. illinoisensis, now synonymized with E. cambaria; light grey represents E. cambaria, and; white represents Entocythere sp.

FIGURE 2. Adult male Entocythere cambaria neotype USNM 1462653 including A) photograph showing entire specimen; B) illustration of carapace, including cracks as they appear in its current state; C) photograph of entire copulatory complex of E. cambaria neotype USNM 1462653 in situ, with notations for peniferum (p), clasping apparatus (ca), dorsal finger (df), and ventral finger (vf); D) illustration of one of the paired halves of the copulatory complex of E. cambaria neotype USNM 1462653; E) illustration of one of the paired halves of the copulatory complex of allotype adult male E. illinoisensis USNM 8190; F) illustration of the second paired half of the copulatory complex of allotype adult male E. illinoisensis USNM 8190, bearing a bifid dorsal finger; D.1, D.2) each of the two clasping apparatuses isolated, E. cambaria neotype USNM 1462653, and; E.1, E.2) each of the two clasping apparatuses isolated from E and F, respectively, allotype adult male E. illinoisensis USNM 8190. Scale bar (100 µm) shared by A and B. Scale bar (10 µm) shared by C, D, D.1, D.2, E, E.1, F, F.1.

FIGURE 3. Illustrations of appendages of adult male E. cambaria neotype USNM 1462653 including, A) antennule, B) antenna, C) mandible, D) rake-shaped organ, E) maxillula, F) fifth limb, G) sixth limb, and H) seventh limb. Scale bar 10 µm.

FIGURE 4. Adult female E. cambaria USNM 1462654 including A) photograph showing the entire specimen; B) illustration of carapace; C) illustration of antenna; D) photograph showing pectinate appendages at base of antennal claw; E) illustration of fifth limb; F) illustration of genital complex, and; G) photograph of genital complex. Scale bar (100 µm) shared by A and B. Scale bar (10 µm) shared by C and D; F and G. Scale bar for E 10 µm.