Corresponding author: Rita S.W. Yam (
Academic editor: Andre Bochkov
New records of water mites (Acari: Hydrachnidia) from Baishih River drainage of north Taiwan, are presented. Twelve species are recorded, of which ten are new for Taiwan; two of them,
Taiwan is a large island (35, 881 km2) located in the Asian Pacific region. As the Tropic of Cancer bisects the Island, the climate changes from subtropical to tropical from the northern to southern parts of the island. The climate of Taiwan is heavily influenced by monsoons and typhoons which bring an annual rainfall of ~ 2150 mm, with 80% of precipitation concentrated in the summer (or wet season), i.e. May–October. As there is a central mountain range extending from the north to the south of the island with surrounding plateau and hills, two third of the island is covered by mountainous area with an elevation 100–>3000 m. All rivers in Taiwan are characterized by short length and steep gradient with rapid flows and small drainage basins associated with the steep terrain. Such diverse patterns of geographical typology and hydrology result in the high levels of habitat heterogeneity and aquatic biodiversity of the Taiwan rivers (
Water mites are one of the most ubiquitous components of the lotic communities. However, detailed investigation on their taxonomy, distribution and ecology is generally lacking in the Asian Pacific region. Furthermore, the water mite fauna of Taiwan is very incompletely known. Recently, we published the results of the first collection of water mites from Taiwan, listing three species of the family
Map of study area showing location of the six sampling sites.
Baishih River system is located in the northern Taiwan. It is one of the major upstream feeder tributary of the urbanised Xindian River which runs into Danshui River in the New Taipei City. Baishih River originates from both Mount Sanfonsun and Mount Yingtzuling, and drains southwestward into Feitsui Reservoir which provides water supply for the population of the Taipei metropolitan area. Baishih River is ~50 km long and the catchment area is about 310 km2. The present study focused on two major tributaries Chinkualiao Stream and Diyu Stream of Baishih River drainage. All study sites are relatively undisturbed by human activities as both Chinkualiao Stream and Diyu Stream are located within the protected area. The riparian area is dominated by natural forest with discontinuous distribution of cultivated land owned by local villagers.
The paper aims to describe the diversity and distribution pattern of water mites from the northern Taiwan. In the present study, twelve species are identified, two of them are new to science. Descriptions of these species are given in this paper.
In this study, water mites were collected at six sampling sites (
List of the sampling sites in the present study.
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BA-1 |
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Baishih River | Chinkualiao Stream | 365 | |
BA-2 |
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Baishih River | Chinkualiao Stream | 343 | |
BA-3 |
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Baishih River | Chinkualiao Stream | 250 | |
BA-4 |
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Baishih River | Diyu Stream | 232 | |
BA-5 |
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Baishih River | Diyu Stream | 210 | |
BA-6 |
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Baishih River | Diyu Stream | 190 |
Photographs of the six study sampling sites in the present study.
In the section ‘Material examined’, the sampling site codes were derived from the geographical database Rita Yam (see
ECL-BA-1: 01.vii.2010 0/1/0 (mounted).
Due to the presence of a single, short swimming hair on segments four and five of the third and fourth legs and the shape of palp (
India, Indonesia, Iran, Oman, Balkan. New for Taiwan.
ECL-BA-3: iii.2010 0/1/0 (mounted). ECL-BA-5: iii.2010 0/1/0.
The two females examined in the present study fit well the description of
Burma, China (Guizhou Province), Turkey, Iran. New forTaiwan.
ECL-BA-2: iii.2010 1/1/0. ECL-BA-3: vi.2010 0/1/0 (mounted). ECL-BA-4: iii.2010 5/0 1/0/0 (mounted); iv.2010 0/1/0; 27.vii.2010 1/1/0. ECL-BA-5: iii.2010 1/1/0; iv.2010 0/1/0. ECL-BA-6: iv.2010 0/2/0.
The specimens from Baishih River drainage are provisionally assigned to the Oriental species
SE Asia, China (Guizhou Province). New forTaiwan.
ECL-BA-1: 10.viii.2009 0/1/0; iii.2010 0/1/0; 01.vii.2010 0/1/0 (mounted); 02.vii.2010 0/2/0; 30.x.2010 1/0/0. ECL-BA-2: 27.vii.2010 2/0/0 (1/0/0 mounted). ECL-BA-3: 23.ix.2009 0/1/0; iii.2010 0/1/0. ECL-BA-4: iii.2010 0/1/0; 27.vii.2010 1/2/0 (1/1/0 mounted). ECL-BA-5: iv.2010 0/1/0. ECL-BA-6: iii.2010 0/1/0.
The specimens examined from Baishih River drainage agrees with the description of
Indonesia. New for Taiwan.
ECL-BA-1: 07.vii.2009 1/1/0; 23.ix.2009 2/0; iv.2010 13/0; 01.vi.2010 1/0; vii.2010 29/0; 27.vii.2010 2/1/0. ECL-BA-2: 02.ix.2009 11/2(1juvenile)/0; ii.2010 57/0; iii.2010 3/1/1; iv.2010 0/2/0; vi.2010 2/2/0; 27.vii.2010 17/0; 29.ix.2010 5/0; 30.x.2010 1/0. ECL-BA-3: 01.vii.2009 1/0/0; 23.vii.2009 1/0/0; ii.2010 4/11/0; ii.2010 10/0; iv.2010 0/1/0; 27.vii.2010 1/0/0. ECL-BA-4: 02.vii.2009 1/0/0; ii.2010 2/1/0; iii.2010 6/4/0; iv.2010 0/1/0; vi.2010 1/0/0; vii.2010 19/0; 27.vii.2010 5/0/0; 30.x.2010 1/0. ECL-BA-5: iii.2010 1/1/0; 01.vi.2010 4/0/0; vii.2010 11/0; 07.vii.2010 1/0/0; 30.x.2010 1/0/0. ECL-BA-6: 17.vi.2009 3/0; iii.2010 2/9/0; vi.2010 0/1/0; 01.vii.2010 1/0/0; 27.vii.2010 1/0/0; 29.ix.2010 1/0.
It is the most abundant species in our material. For an analysis of diagnostic characters of populations from Taiwan tentatively assigned to
Malaysia, Thailand, Taiwan.
ECL-BA-1: 07.vii.2009 1/0/0. ECL-BA-3: 27.vii.2010 1/4/0. ECL-BA-4: 02.vii.2009 0/2/0; ii.2010 0/1/0; iii. 2010 0/4/0; iv.2010 0/1/0 (mounted); vi.2010 1/1/0; 27.vii.2010 0/1/0; ECL-BA-5: 21.vii.2009 1/0/0; iii.2010 0/2/0; 01.vi.2010 1/1/0; 07.vii.2010 0/1/0. ECL-BA-6: ii.2010 1/0/0; iii. 2010 0/6/0; 27.vii.2010 0/1/0; 29.ix.2010 3/0.
The studied material was collected from February to September. For an analysis of diagnostic characters of
Taiwan.
Holotype male (NMNS-6894-002), dissected and slide mounted, Taiwan, BA-1, Baishih River drainage, Chinkualiao Stream, 27.vii.2010. Paratype: one male, same data as holotype; one male, dissected and slide mounted, BA-2, Chinkualiao Stream, 02.ix.2009.
Male (female unknown). Cx-IV extending posterior to genital field; excretory pore posterior to line of primary sclerotization, Vgl-2 slightly posterior to excretory pore; capitulum with a short rostrum; medial suture line of Cx-II+III short; P-2 ventrodistal projection cone-shaped, pointed towards distal, P-3 ventrodistal projection larger than projection of P-2, P-3 with a long tapering ventral protrusion which curves distally.
Male (holotype, in parentheses measurements of paratype, n = 1) — Idiosoma (ventral view:
The species is named after the distinctive shape of ventrodistal projection of P-3; ‘
The shape of ventrodistal projection of P-3 of the new species is very distinctive and can separate it from all other
Taiwan.
Holotype female (NMNS-6894-001), dissected and slide mounted, Taiwan, BA-3, Chinkualiao Stream, vi.2010. Paratypes: 0/1/0, same data as holotype; 1/1/0 (mounted), BA-1, Chinkualiao Stream, iii. 2010; 0/3/0, BA-4, Diyu Stream, iii.2010; 0/1/0, BA-5, Diyu Stream, iv.2010.
Idiosoma L > 750; acetabula arranged in an obtuse angle; female pregenital sclerite with four setae, its anterior margin extending beyond anterior margin of genital plates; female genital plates longer than gonopore; posterior end of female genital plates posterior to postgenital sclerite; P-2 ventrodostal projection elongate, cone-shaped; proximoventral seta on P-4 longer and thicker than distoventral seta.
Female (holotype, in parentheses paratype). Idiosoma L 775 (778), W 613 (706); integument soft, with very fine striation. Capitulum broadly fused with Cx-I. Coxae (
Males (n = 2): similar to female, except for genital field. Idiosoma L 775-794, W 625-656; coxal field L 338, Cx-III W 463, Cx-I+II L/W 231/334; genital field L/W 160-170/148-151, anterior margin convex, L Ac-1-3: 51-58, 63-66, 63-66; ejaculatory complex L 169. Palp (
The species is named for its occurrence in Taiwan.
The new
ECL-BA-3: 23.ix.2009 4/0; ii.2010 0/3/0; vi.2010 2/0. ECL-BA-4: 17.vi.2009 1/0/0. ECL-BA-5: iv.2010 1/0/0; 07.vii.2010 5/0; 27.vii.2010 19/0; 30.x.2010 0/2/0. ECL-BA-6: 17.vi.2009 3/2/0; 17.vi.2009 7/0; vi.2010 0/3/0; 01.vii.2010 2/0/0; 27.vii.2010 12/0 (0/1/0 mounted); 29.ix.2010 0/1/0.
The most abundant
Palaearctic. New for Taiwan.
ECL-BA-3, vi.2010 0/1/0 (mounted). ECL-BA-5, 20.viii.2009 0/1/0.
The specimens from Taiwan are in a good agreement with description of the Oriental
In addition, we gave some measurements of the specimen of
Female. Idiosoma L/W 881/625. Coxae (
SE Asia, India, New Guinea, Australia, Iran. New for Taiwan.
ECL-BA-1: 01.vi.2009 0/1/0; 02.vii.2010 0/1/0. ECL-BA-2: iv.2010 0/2/0; vi.2010 0/1/0. ECL-BA-3: 03.ix.2009 0/3/0. ECL-BA-4: iii.2010 0/4/0 (0/1/0 mounted); iii.2010 0/1/0. ECL-BA-5: iv.2010 0/1/0; 07.vii.2010 0/4/0. ECL-BA-6: iii.2010 0/1/0; iv.2010 0/2/0; vi.2010 0/1/0; ix.2010 0/1/0.
The examined female specimens from Baishih River system resemble Oriental
SE Asia. New for Taiwan.
ECL-BA-1: 23.ix.2009 0/1/0. ECL-BA-4: 20.viii.2009 0/1/0; 27.vii.2010 0/2/0. ECL-BA-5: 27.vii.2010 0/3/0; x.2010 0/1/0. ECL-BA-6: 01.vii.2010 0/1/0; 27.vii.2010 0/1/0; 30.x.2010 0/1/0 (mounted).
See discussion under
SE Asia. New for Taiwan.
This study was supported by the research grants NSC100-627-B-002-009- and NSC101-2923-B-002-001-MY3 from the National Science Council, ROC. The authors also acknowledged the Agriculture Department from the New Taipei City Government for issuing the field sampling permit at the Baishih River during the study period. We are thankful to the anonymous referee for the careful work and valuable comments.