Branchinecta constricta
| Notice: | This page is derived from the original publication listed below, whose author(s) should always be credited. Further contributors may edit and improve the content of this page and, consequently, need to be credited as well (see page history). Any assessment of factual correctness requires a careful review of the original article as well as of subsequent contributions.
If you are uncertain whether your planned contribution is correct or not, we suggest that you use the associated discussion page instead of editing the page directly. This page should be cited as follows (rationale):
Citation formats to copy and paste
BibTeX: @article{Rogers2006Zootaxa1126, RIS/ Endnote: TY - JOUR Wikipedia/ Citizendium: <ref name="Rogers2006Zootaxa1126">{{Citation |
Ordo: Anostraca
Familia: Branchinectidae
Genus: Branchinecta
Name
Branchinecta constricta Rogers, D. Christopher, 2006 – Wikispecies link – Pensoft Profile
- Branchinecta constricta Rogers, D. Christopher, 2006, Zootaxa 1126: 42-45.
Description
Types: Holotype, male, data: USA: WYOMING; Sweetwater Co.: Antelope Pocket Overlook Rock Pool (42 º 40 ’ 26 ”N, 107 º 54 ’ 39 ”W), 15 June 1989, G. D. Langstaff, deposited: National Museum of Natural History, Washington D.C. USNM1014985. Paratypes: same data as holotype, 3 females, 4 males, deposited: National Museum of Natural History, Washington D.C. USNM1014986.
Materials Examined
Material Examined: USA. WYOMING: Albany County: Todd’s Rock Pool I, Laramie Range, Veedauwoo Area, 2597m elevation, 41 º 09’ 44 ”N, 105 º 22 ’ 32 ”W, 20 May 1989, G. D. Langstaff. Todd’s Rock Pool II, 30m northwest of Pool I, Veedauwoo Area, 2597m elevation, 41 º 09’ 44 ”N, 105 º 22 ’ 32 ”W, 20 May 1989, G. D. Langstaff. Todd’s Rock Pool III, 50m eastnortheast of Pool I, Veedauwoo Area, 2597m elevation, 41 º 09’ 44 ”N, 105 º 22 ’ 32 ”W, 17 May 1992, G. D. Langstaff. Todd’s Rock Pool IV, 20m west of Pool I, Veedauwoo Area, 2597m elevation, 41 º 09’ 44 ”N, 105 º 22 ’ 32 ”W, 17 May 1992, G. D. Langstaff. Fremont County: Antelope Pocket Overlook Rock Pool, Western Granite Mountains, 2178 m elevation, 2 km southeast of Wildhorse Rock Pool, 42 º 40 ’ 26 ”N, 107 º 54 ’ 39 ”W, 15 June 1989, G. D. Langstaff. Antelope Pocket Overlook Rock Pool, 2178 m elevation, 42 º 40 ’ 26 ”N, 107 º 54 ’ 39 ”W, 8 May 1989, G. D. Langstaff. Antelope Pocket Overlook Rock Pool, 2178 m elevation, 42 º 40 ’ 26 ”N, 107 º 54 ’ 39 ”W, 19 August 1987, G. D. Langstaff. Lankin Dome Summit Pool #1, 42º 31 ’ 50 ”N, 107 º 33 ’ 40 ”W, 2316 m elevation, 4 June 1990, G. D. Langstaff. Lankin Dome Summit Pool #2, 42º 31 ’ 50 ”N, 107 º 33 ’ 40 ”W, 2316 m elevation, 4 June 1990, G. D. Langstaff. Dead Antelope Rock Pool, 2181 m elevation, 42 º 39 ’ 26 ”N, 107 º 53 ’ 30 ”W, 8 May 1992, G. D. Langstaff. Type Locality. Antelope Pocket Overlook Rock Pool (42 º 40 ’ 26 ”N, 107 º 54 ’ 39 ”W) is in the Western Granite Mountains, on the south side of the Beaver Divide, at 2178 m elevation, in Fremont County, Wyoming. The pool is in Sagebrush steppe, is roughly 1.5 meters in length, and is only a few centimeters deep. The water is clear to slightly turbid.
Etymology
Etymology. The specific epithet describes the characteristic constriction of the male and female second antennae. The gender is feminine.
Description
Description. Male. Average length of preserved material 16 mm. Head smooth, anteriorlateral corners projecting over eye peduncles. First antenna 1.5 to 2 times as long as eye plus stalk. First antenna 0.25 to 0.5 times as long as second antenna proximal antennomere. Second antennae extending posteriorly to sixth or seventh thoracic segment. Second antenna stout, 2–2.5 times as long as broad. Proximal antennomere subcylindrical, pulvillus present, and with an anteriolateral tubercle in the proximal fourth (Figure 2 D). Apophyses absent. Proximal antennomere bearing a transverse groove just distad of the pulvillus, giving the segment a “constricted” appearance. Transverse groove diminishes with age. Pulvillus and lateral tubercle with large, cylindrical, evenly spaced spines that may continue across the anterior surface of the proximal segment, as well as distally into the transverse groove in older males. Medial surface bearing a stout tubercle covered with fine denticles.
Second antennal distal antennomere 0.75 times the length of the proximal antennomere; robust basally at point of articulation. Antennomere flattened laterally (twice as broad as thick), basal half arcuate medially and parallel sided; distal half straight, margins explanate, with widest point just prior to apex; apex bent medially 90 °, directed anteriorly, subtruncate distally (Figure 2 A–C, 3). Labrum smooth, distal lobe projecting ventrally, rounded posteriorly. Mandibles with molar surface covered with fine denticles, posterior spine reduced and blunt. Maxilla 1 and 2 typical for the genus. Praepipodites and epipodites typical for the genus. Thoracopod I with exopodite ovate, with apex slightly directed ventrally, and margined with fine setae. Endopodite margined with stout setae, subtriangular, with apex slightly directed ventrally. Endite 1 + 2 and 3 margined with long plumose setae. Endite 4 with stout anterior setae and stout posterior pectinate seta. Endite 5 with stout anterior and posterior. Endite six with stout posteriorly directed pectinate setae. Thoracopod V with exopodite oval in outline, endopodite elongate triangular. (Figure 2 G). Exopodite margined with fine plumose setae. Endopodite margined with stout setae, with distal most setae pectinate, becoming short and medially curved on the medioventral margin. Endite 1 + 2 and 3 margined with long filiform setae bearing short, fine setules. Endite 3, 4 and 5 with setae similar to endites 1 + 2. Endite 6 with pectinate setae. Thoracopod XI with exopodite rounded, blunt, and endopodite oval. Exopodite and endopodite margined with fine setae. Endites margined with sparse stout setae. Penes extending to base of abdominal segment 2. Medial spur arcuate, 3 times as long as broad, bending posteriorly. Penes with distoapical “wartlike” mounds on lateral surface, directed posteriorly with 5 to 10 apical spines.
Female. Average length of preserved material 14 mm. Head smooth, without projections. Maxillary glands large, typically asymmetrical. First antenna twice as long as eye plus stalk, and half as long as second antenna. Second antenna 2.5–3 times as long as broad, apex subacute. Six percent of females with second antenna proximalmedial surface bearing a small, slender spine. Second antenna lateral surface with a small tubercle bearing fine spines. (Figure 2 E, H). Thoracic segments IV–XII with dorsallateral subconical projections, the largest on segments V–VIII. Endopodite ovate, exopodite falcate to ovate (Figure 2 F). Thoracopod setal arrangement similar to male. Ovaries extend anteriorly to the eighth or ninth thoracic segment, and posteriorly to abdominal segment 4 or 5. Brood pouch subcylindrical, extending to abdominal segment four or five. Cercopods in less than 10 % of females (64) may be extremely short; only one fourth or less the length of the telson. Otherwise the cercopods are as in the male. Cyst. Approximately 320 µm in diameter and typical for the genus. Surface with shallow polygons 10 to 15 µm across bordered by low rounded ridges. Differential diagnosis. Male B. constricta are separated from all other Branchinecta species by the second antennal proximal segmentís transverse invagination, appearing as a “constriction”. B. constricta most closely resembles B. coloradensis Packard, 1874 and B. packardi Pearse, 1912 (see Lynch, 1964). All three species share a bulge or projection on the second antennal medial surface; however in B. coloradensis the bulge is spinose, and in B. packardi the medial projection is directed anteriorly. In B. constricta the medial projection is blunt and directed medially. B. coloradensis and B. packardi are also both readily separated from B. constricta by the presence of proximal posteriomedial apophyses on the second antennae. Female B. constricta can be separated from all other female Branchinecta species by the dorsal thoracic ornamentation. Female B. constricta are most similar to B. packardi females. Both taxa share the large maxillary glands, and have similar brood pouch morphology and similar dorsolateral projections. However, in B. packardi the projections are angular and directed posteriorly, and are present only on thoracic segments nine through twelve.
Distribution
Distribution and Habitat. B. constricta is apparently endemic to Wyoming, but may occur in northern Colorado. To date all of the locations for this species have been small pools, under 2.5 meters across, and only a few centimeters deep. It is possible that this species is opportunistic, surviving in shallow peripheral pools. Nearby larger habitats are typically occupied by B. lateralis, B. readingi, or B. serrata. IUCN Red List Status. This species is currently known only from eight locations in southcentral and southeastern Wyoming. Therefore this species meets the International Union for the Conservation of Nature and Natural Resources (IUCN) red list criteria for designation as a VU D 2 species (IUCN, 2000). That is to say, this taxon is vulnerable due to the population being very small and restricted, that may be prone to the effects of human activities or stochastic events within a short period of time.
Taxon Treatment
- Rogers, D. Christopher; 2006: Three new species of Branchinecta (Crustacea: Branchiopoda: Anostraca) from the Nearctic, Zootaxa 1126: 42-45. doi
This treatment was originally uploaded by Plazi, compare this treatment on Plazi. Unless this treatment has been substantially changed on Species-ID, Plazi requests to maintain a link back to the original repository.
