Brancelia sketi Damme & Sinev, 2011
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publication ID |
https://doi.org/ 10.1111/j.1096-3642.2010.00639.x |
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persistent identifier |
https://treatment.plazi.org/id/039E87B1-FFF8-0B30-C9DF-F956FD2CF9CA |
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treatment provided by |
Valdenar |
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scientific name |
Brancelia sketi |
| status |
comb. nov. |
BRANCELIA SKETI ( BRANCELJ, 1992) COMB. NOV.
( FIGS 4 View Figure 4 , 5 View Figure 5 )
= Alona sketi Brancelj, 1992 View in CoL ; Brancelj (1992: figs 1, 2; pl. 1); Brancelj & Dumont (2007).
Type locality: Cave Osapska Jama , Koper, south-west Slovenia . Type material see Brancelj (1992).
Material examined: Three complete adult parthenogenetic females and one dissected adult parthenogenetic female. Cave Osapska Jama , Koper, south-west Slovenia. Leg. A. Brancelj, 19.IX.1990. Collection UGent .
Redescription of adult parthenogenetic female: Body ( Fig. 4A, B View Figure 4 ) ovoid, arched in lateral view, with strongly convex circular ventral margin, deepest point at middle; length 0.4–0.46 mm with body 1.3 times as long as high. Posterior valve margin strongly convex, with embayment just below posterodorsal corner ( Fig. 4A, B View Figure 4 ). Head with separate rostrum ( Fig. 2B View Figure 2 ) and widely obtuse tip, in lateral view not reaching over labral keel and about two-thirds of body height ( Fig. 4A View Figure 4 ); three major connected head pores and two lateral pores, PP distance about 1.7 IP ( Fig. 4H View Figure 4 ), distance to small pores not measured. Carapace with wide striation ( Fig. 4B View Figure 4 ); posteroventral corner rounded, no notch; marginal setae with anterior group clearly longer ( Fig. 4E View Figure 4 ), about twice as long as median and posterior groups (posterior even a little longer than median), posterior setae not decreasing strongly in length towards posteroventral corner, row ending before unmarked posteroventral corner; setae relatively short and acute; setae followed by fine spinules, not arranged in groups, continuing close to and parallel with margin (no notch), extending beyond it ( Fig. 4E View Figure 4 ). Postabdomen ( Fig. 4I View Figure 4 ) shape broad, about two to 2.5 times as long as wide, with deepest point at preanal corner; anal margin longer than postanal margin; acute preanal angle, moderately expressed (triangular with broad base), not reaching far beyond postanal angle; postanal margin straight, tapering distally, and markedly separate from anal margin. Anal margin rather concave. Postabdomen armature with about seven to eight postanal marginal denticles consisting of unmerged groups (small spines); lateral fascicles as for genus, spinules per group even less differentiated. Five to six lateral fascicle groups close to margin, not accompanied by extra groups above (actually below) it; marginal denticles all similar in length per group and consisting of four denticles each; marginal denticles of anal margin of similar spines in about five groups. Terminal claw ( Fig. 4I View Figure 4 ) shorter than anal margin, curved. Basal spine longer (1.25 times) than claw width at base, about one-third of claw length and with basal spinules. First antenna ( Fig. 4F View Figure 4 ) as for previous species, but about three times as long as wide and sensory seta reaching over antennular apex. Second antenna ( Fig. 4G View Figure 4 ) as for genus, with first exopod spine about half as long as second segment, terminal spines about half as long as terminal segments. First endopod seta reaching onequarter of its length over antennal apex. Labrum as for genus, with straight to moderately convex margin and an obtuse tip without indentation; keel with one basal row of small ventral setules.
First maxilla with two thick, setulated setae. Five pairs of limbs. First limb ( Fig. 5A–D View Figure 5 ). First endite ( Fig. 5A–B View Figure 5 ) with three marginal setae of which dorsal one reduced (about three to four times its width at base), second and third endites as for genus ( Fig. 5A View Figure 5 ); anterior elements or soft setae on en1–2 ( Fig. 5B View Figure 5 ) reduced and about two to three times as long as wide, second longer than first. ODL ( Fig. 5C View Figure 5 ) with one slender seta with short setules in distal half, IDL with three setae of which third seta naked ( Fig. 5D View Figure 5 ), reaching one-third of shortest IDL seta; longest two setae unmodified and with fine long setules in distal halves, longest similar in length to ODL seta. Accessory seta present, well developed and shorter than ODL seta ( Fig. 5C View Figure 5 ). Anteriorly on corm ( Fig. 5A View Figure 5 ), six to seven setule groups with more than six fine setules in each group; setules in each group do not decrease in size ventrally. Ejector hooks as for genus, epipodite ovalround with finger-like projection not reaching over limb. Second limb ( Fig. 5E, F View Figure 5 ). Exopodite ( Fig. 5E View Figure 5 ) with well-developed seta, about as long as exopodite itself; exopodite rectangular to oval and about two times as long as wide; endites ( Fig. 5E View Figure 5 ) with eight scrapers, all slender and with fine denticles, of which last (eight) shortest. Near base of first scraper, a large anterior soft seta or element, about one-ninth of scraper length ( Fig. 5F View Figure 5 ). Scraper morphology ( Fig. 5E View Figure 5 ). First two scrapers of similar lengths, scraper three markedly shorter than second and fourth, both latter scrapers shorter than fifth. Scrapers five to eight gradually decreasing in length towards gnathobase. Gnathobasic ‘brush’ extended, gnathobase with sensillum and three modified elements of which first a bent seta; filter comb with seven setae (not drawn) of which first shortest and thickest. Third limb ( Fig. 5G–K View Figure 5 ). Exopodite ( Fig. 5G, H View Figure 5 ) with rectangular corm and seven long setae in 2 + 5 arrangement; first two setae with first about twice as long as second, third exopodite seta longest, fourth and fifth unequal with fourth longer than fifth. Fifth seta reaching half of fourth; sixth 1.8 times seventh seta ( Fig. 5H View Figure 5 ). External endite ( Fig. 5I View Figure 5 ) with three setae (1′–3′) of which first two (1′–2′) very long (at least twice length of seta 3′), first longer than second, with two minute elements in between; four well-developed plumose setae with plump basis on inner side (1′–4′); one elongated naked element and four relatively long setae with small setules on internal endite preceding gnathobase ( Fig. 5J View Figure 5 ); gnathobase ( Fig. 5K View Figure 5 ) with large cylindrical sensillum and large plumose seta. Filter comb with seven long setae of similar length (not shown). Fourth limb ( Fig. 5L–N View Figure 5 ). Epipodite oval–round, with fingerlike projection reaching beyond centre of exopodite ( Fig. 5L, M View Figure 5 ). Exopodite ( Fig. 5L View Figure 5 ) rectangular, with six plumose setae of which first two similar lengths and shorter than third, fifth longer than third; fifth and sixth setae of similar thickness than others, fifth longer than sixth. Fourth seta markedly shorter, nearly half of third seta. Endite ( Fig. 5N View Figure 5 ) with marginal row of four setae (1′–4′), first scraper-like, longer than flaming torch setae and leaning backwards; three flaming torch setae of which first longer than wide, decreasing in size towards gnathobase and one naked sensillum, about twice as long as wide, on margin; gnathobase ( Fig. 5N View Figure 5 ) with one seta, bent over endite, reaching as far as third scraper and one reduced naked element; on inner side, three well-developed plumose setae; fc with five setae. Fifth limb ( Fig. 5P, Q View Figure 5 ). Epipodite round, with finger-like projection reaching beyond exopodite centre ( Fig. 5P View Figure 5 ). Exopodite shape oval, about twice as long as wide, with deep concave margin between setae three and four; four exopodite setae, of which first to third of similar lengths, shorter than exopodite length itself (0.7 times) and orientated dorsally; inner portion ( Fig. 5Q View Figure 5 ) as for genus, but fc not seen. Adult male and ephippial female unknown.
Differential diagnosis: Brancelia sketi has a postabdomen with straight postanal dorsal margin that tapers distally and groups of more than two marginal denticles. On second antenna, first exopod seta relatively short, up to 1.4 times length of second and third exopod segments together; in B. stochi and B. hercegovinae this seta about twice as long as last two segments. Labral keel in B. sketi straight, without indentation towards apex. Limb characters: first seta in P1 (en1) present but short (three to four times as long as wide), P2 with third to fifth scrapers of similar length; relatively longer exopodite setae on P3 (fifth seta) and P4 (fifth seta) when compared to B. stochi and B. hercegovinae ; specimens examined here with P4–P5 with long epipodite projections.
Distribution and biology: Slovenia, cave Osapska Jama, periodical cave spring ( Brancelj, 1992). Stygobiont regularly found in amphibious part of the cave and accompanied by stygobiont crustaceans like Sphaeromides virei ( Brian, 1923) , Troglocaris cf. schmidti Dormitzer, 1853 and Troglodiaptomus sketi Petkovski, 1978 ( Brancelj, 1992; Brancelj & Dumont, 2007). Found in pools with solid rock bottom or sand covered with fine clay with almost no organic matter; water temperatures c. 12 °C ( Brancelj, 1992). In life, with limited swimming abilities; this species lives in close contact with substrate and hardly moves into the water column (A. Brancelj, pers. comm.).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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Brancelia sketi
| Damme, Kay Van & Sinev, Artem Y. 2011 |
Alona sketi
| Brancelj 1992 |