Limits...
A new species of Metacyclops from a hyporheic habitat in North Vietnam (Crustacea, Copepoda, Cyclopidae).

Kołaczyński A - Zookeys (2015)

Bottom Line: The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki).The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam.An identification key is provided to the south and east Asian species of the genus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Museum and Institute of Zoology Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland.

ABSTRACT
A new species of Metacyclops is described from hyporheic waters and small rock depression with leaf litter in North Vietnam, the Tam Đao Mountains). Metacyclops amicitiae sp. n. can be distinguished from its congeners by the unique combination of the following characters: 12-segmented antennule, distal segment of P4 endopodite bearing a single apical spine, and the surface ornamentation of the intercoxal sclerites in P1-P4 (pilose on the distal margin of P1-P4 and spinulose on the caudal surface of P4). The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki). The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam. An identification key is provided to the south and east Asian species of the genus.

No MeSH data available.


Related in: MedlinePlus

Records of Metacyclopsamicitiae sp. n. (•) in North Vietnam and its presumed closest relative Metacyclopsryukyuensis (*) in Japan (Archipelago Ryukyu: Ishigaki Island).
© Copyright Policy - creative-commons-attribution
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4591735&req=5

Figure 5: Records of Metacyclopsamicitiae sp. n. (•) in North Vietnam and its presumed closest relative Metacyclopsryukyuensis (*) in Japan (Archipelago Ryukyu: Ishigaki Island).

Mentions: The 12-segmented antennule in the female of Metacyclopsamicitiae sp. n. is a very rare trait among the Old World Metacyclops taxa. The only other species that shows the same segmentation pattern is Metacyclopsryukyuensis from Ishigaki Island, Ryukyus, Japan (Fig. 5) (Ishida, 1995). However, the 12-segmented state of the antennule is not unusual among the Middle and South American taxa [Metacyclopsbrauni Herbst, 1962, Metacyclopsbotosaneanui Pesce, 1985, Metacyclopshartmani Herbst, 1960, Metacyclopslaticornis (Lowndes, 1934), Metacyclopsnecessarius (Kiefer, 1926), Metacyclopsmendocinusvenezolanus Kiefer, 1956, Metacyclopsleptopus (Kiefer, 1927), Metacyclopsleptopusmucubajiensis Kiefer, 1956, Metacyclopsmendocinus (Wierzejski, 1892), Metacyclopsproblematicus Dumont, 1973, Metacyclopsjanstocki Herbst, 1990, Metacyclopshirsutus Rocha, 1994] (see Herbst 1988, 1990; da Rocha 1994), but those New World species have two spines on the distal endopodal segment of P4, instead of the single one present in Metacyclopsamicitiae and Metacyclopsryukyuensis. Metacyclopsamicitiae sp. n. differs from Metacyclopsryukyuensis in the surface ornamentation of the intercoxal sclerites of the swimming legs (sclerites smooth in Metacyclopsryukyuensis vs. sclerites bearing distal hairs in P1-P4, and spinules on the caudal surface of P4 both in female and male of Metacyclopsamicitiae). Other characters that also distinguish Metacyclopsamicitiae sp. n. from Metacyclopsryukyuensis are: number of setae on the second endopodal segment of the female antenna (nine in the new species, eight in Metacyclopsryukyuensis); the size of the posterior sac of the seminal receptacle (long, approaching posterior margin of the genital double-somite in Metacyclopsamicitiae sp. n., vs. reaching nearly the middle of the somite in Metacyclopsryukyuensis); P4 coxopodite with five rows of spinules on the caudal surface, robust spinules near the proximal margin of the segment in Metacyclopsamicitiae, vs. four rows of spinules, tiny spinules near the proximal margin of the coxopodite in Metacyclopsryukyuensis; apical spine of P4 endopodite is 0.82 times as long as distal segment in Metacyclopsamicitiae, vs. 0.67 times as long as distal segment in Metacyclopsryukyuensis; genital double-somite wider than long in Metacyclopsamicitiae, vs. as long as wide in Metacyclopsryukyuensis; presence of spinules at insertion of the anterolateral caudal setae in Metacyclopsamicitiae sp. n., vs. absence in Metacyclopsryukyuensis, and finally surface ornamentation of the anal sinus (naked in Metacyclopsamicitiae sp. n., with spinules in Metacyclopsryukyuensis).


A new species of Metacyclops from a hyporheic habitat in North Vietnam (Crustacea, Copepoda, Cyclopidae).

Kołaczyński A - Zookeys (2015)

Records of Metacyclopsamicitiae sp. n. (•) in North Vietnam and its presumed closest relative Metacyclopsryukyuensis (*) in Japan (Archipelago Ryukyu: Ishigaki Island).
© Copyright Policy - creative-commons-attribution
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591735&req=5

Figure 5: Records of Metacyclopsamicitiae sp. n. (•) in North Vietnam and its presumed closest relative Metacyclopsryukyuensis (*) in Japan (Archipelago Ryukyu: Ishigaki Island).
Mentions: The 12-segmented antennule in the female of Metacyclopsamicitiae sp. n. is a very rare trait among the Old World Metacyclops taxa. The only other species that shows the same segmentation pattern is Metacyclopsryukyuensis from Ishigaki Island, Ryukyus, Japan (Fig. 5) (Ishida, 1995). However, the 12-segmented state of the antennule is not unusual among the Middle and South American taxa [Metacyclopsbrauni Herbst, 1962, Metacyclopsbotosaneanui Pesce, 1985, Metacyclopshartmani Herbst, 1960, Metacyclopslaticornis (Lowndes, 1934), Metacyclopsnecessarius (Kiefer, 1926), Metacyclopsmendocinusvenezolanus Kiefer, 1956, Metacyclopsleptopus (Kiefer, 1927), Metacyclopsleptopusmucubajiensis Kiefer, 1956, Metacyclopsmendocinus (Wierzejski, 1892), Metacyclopsproblematicus Dumont, 1973, Metacyclopsjanstocki Herbst, 1990, Metacyclopshirsutus Rocha, 1994] (see Herbst 1988, 1990; da Rocha 1994), but those New World species have two spines on the distal endopodal segment of P4, instead of the single one present in Metacyclopsamicitiae and Metacyclopsryukyuensis. Metacyclopsamicitiae sp. n. differs from Metacyclopsryukyuensis in the surface ornamentation of the intercoxal sclerites of the swimming legs (sclerites smooth in Metacyclopsryukyuensis vs. sclerites bearing distal hairs in P1-P4, and spinules on the caudal surface of P4 both in female and male of Metacyclopsamicitiae). Other characters that also distinguish Metacyclopsamicitiae sp. n. from Metacyclopsryukyuensis are: number of setae on the second endopodal segment of the female antenna (nine in the new species, eight in Metacyclopsryukyuensis); the size of the posterior sac of the seminal receptacle (long, approaching posterior margin of the genital double-somite in Metacyclopsamicitiae sp. n., vs. reaching nearly the middle of the somite in Metacyclopsryukyuensis); P4 coxopodite with five rows of spinules on the caudal surface, robust spinules near the proximal margin of the segment in Metacyclopsamicitiae, vs. four rows of spinules, tiny spinules near the proximal margin of the coxopodite in Metacyclopsryukyuensis; apical spine of P4 endopodite is 0.82 times as long as distal segment in Metacyclopsamicitiae, vs. 0.67 times as long as distal segment in Metacyclopsryukyuensis; genital double-somite wider than long in Metacyclopsamicitiae, vs. as long as wide in Metacyclopsryukyuensis; presence of spinules at insertion of the anterolateral caudal setae in Metacyclopsamicitiae sp. n., vs. absence in Metacyclopsryukyuensis, and finally surface ornamentation of the anal sinus (naked in Metacyclopsamicitiae sp. n., with spinules in Metacyclopsryukyuensis).

Bottom Line: The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki).The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam.An identification key is provided to the south and east Asian species of the genus.

View Article: PubMed Central - HTML - PubMed

Affiliation: Museum and Institute of Zoology Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland.

ABSTRACT
A new species of Metacyclops is described from hyporheic waters and small rock depression with leaf litter in North Vietnam, the Tam Đao Mountains). Metacyclops amicitiae sp. n. can be distinguished from its congeners by the unique combination of the following characters: 12-segmented antennule, distal segment of P4 endopodite bearing a single apical spine, and the surface ornamentation of the intercoxal sclerites in P1-P4 (pilose on the distal margin of P1-P4 and spinulose on the caudal surface of P4). The latter character separates the new Metacyclops from its closest relative, Metacyclops ryukyuensis, known only from the Ryukyu Islands (Ishigaki). The genus Metacyclops with the new species described herein is also for the first time recorded from Vietnam. An identification key is provided to the south and east Asian species of the genus.

No MeSH data available.


Related in: MedlinePlus