Additional record of Batasio merianiensis (Chaudhuri1913), a catfish (Teleostei: Bagridae)
in upper Brahmaputra River drainage in Arunachal Pradesh, India
Lakpa Tamang 1 & Bikramjit Sinha 2
1,2Zoological Survey of India, Arunachal Pradesh Regional Centre, Senki Valley, Itanagar, Arunachal
Pradesh 791113, India
1 lakpatamang@rediffmail.com (corresponding author), 2 sinhaj@gmail.com
Abstract: This paper communicates the extension of
the distribution range of Batasio merianiensis in Sille River
in the upper Brahmaputra drainage, East Siang District, Arunachal Pradesh. Detailed examinations of the specimens
revealed existence of few morphological variations against those reported by Heok Hee Ng in 2009 on the
following characteristics: by having a longer preanal(70.4–73.4 vs. 66.3–68.2% SL); a longer prepectoral(25.1–29.3 vs. 21.4–25.7% SL); a longer adipose-fin base
(22.0–27.6 vs. 16.9–22.2% SL); a shorter post-adipose distance
(11.6–13.4 vs.13.4–15.5% SL); a deeper body at anus (depth
18.3–20.8 vs.15.2–18.4% SL) and broader head (width 17.6–20.0
vs.13.5–16.2 % HL). Few additional characters of the fish are included
along with brief information on its habitat. The LIPUM, the semi-traditional
method of fishing in the river is identified as a major threat to this species.
Keywords: Batasio merianiensis, habitat, possible threat, range
extension, Sille River.
doi: http://dx.doi.org/10.11609/JoTT.o3516.5738-43 | ZooBank:urn:lsid:zoobank.org:pub:1AD8732C-2CFD-4D32-8624-82236D18FF9B
Editor: W. Vishwanath,
Manipur University, Imphal,
India. Date
of publication: 26 May 2014 (online & print)
Manuscript details: Ms #
o3516 | Received 05 February 2013 | Final received 06 May 2014 | Finally
accepted 07 May 2014
Citation: Tamang, L.& B. Sinha (2014). Additional record of Batasio merianiensis (Chaudhuri1913), a catfish (Teleostei: Bagridae)
in upper Brahmaputra River drainage in Arunachal Pradesh, India. Journal
of Threatened Taxa 6(5): 5738–5743; http://dx.doi.org/10.11609/JoTT.o3516.5738-43
Copyright: © Tamang & Sinha 2014. Creative Commons Attribution
4.0 International License. JoTT allows
unrestricted use of this article in any medium, reproduction and distribution
by providing adequate credit to the authors and the source of publication.
Funding: Zoological Survey of India, Kolkata.
Competing Interest: The authors declare no competing interests.
Acknowledgements: We extend our gratitude to Dr. K. Venkataraman, Director, Zoological Survey of India, Kolkata for facilities
provided for this piece of research. Thanks to Dr. Dhrupad Choudhury, Programme
Coordinator (ICIMOD, Kathmandu, Nepal) for his inspiration and encouragement to
conduct ichthyological research in Arunachal Pradesh.
For
figures, images, tables -- click here
Bagrid catfishes of the genus Batasio Blyth, 1860 are species with small head, laterally compressed body that generally
inhabit fast-flowing hill streams and large rivers throughout South and
mainland Southeast Asia. The genus
is characterized by the head with large sensory pores, a pair of prominent
posterior processes present on the anterior part of the vomer,
transversely elongated bar-like entopterygoid and themetapterygoid which are in close contact with the
quadrate but free from the hyomandibular (Mo
1991). They are found in the
sub-Himalayan region ranging from the Indus River drainage to the west, coastal
rivers draining the eastern face of the Annam Cordilleras to the east, and the
Perak River drainage to the south (Ng 2009). With the inclusion of one more species
namely B. convexirostrum (Darshanet al. 2011), the total number of valid species now increased to 17 from the
earlier 16 species reported by Ng (2008).
Batasio merianiensis, a
poorly known species was originally described by Chaudhuri(1913) from a pond at Mariani Junction, Brahmaputra
River drainage in Assam, northeastern India. The original description is exclusively
based on the holotype and the taxonomic analysis
exhibits old fashioned method of measurement without
morphometric data, which is generally difficult to compare with other
congeners. It was after a prolonged
period of about nine decades, Ng (2009) could obtain fresh material from 16km
northwest of Kokrajhar, in the vicinity of Kumapara, Assam. He rediagnosed, redescribedand revalidated its species status. As information on the natural history of this species such as range of
distribution, population size and trend, biology and potential impacts of
anthropogenic threats remain poorly understood, Ng
(2010) retained it under the Data Deficient Category in the IUCN List of
Threatened Species.
Until now five species of Batasio are
recognized from the Brahmaputra River drainage, viz.: B. batasio,
B. fasciolatus, B. spilurus,
B. tengana and B. merianiensis(Ng 2006, 2009). Batasio merianiensis is easily distinguishable from the others
except B. fasciolatus in having dark vertical
bars on the head and body. This
important character is also conspicuous in the present specimens. The important generic character of Batasio is the presence of prominent sensory pores
on the head, description of which was missing in Ng (2009). We have added this here along with other
additional characters.
Ichthyologicalsurvey in the upper Brahmaputra River basin revealed existence of undiscovered
populations of Batasio in SilleRiver, which was later identified as B. merianiensis. There is no report of this poorly known
species, its habitat or the anthropogenic threats it faces in this region, hence
the present study serves to document this information.
Materials and Methods
Surveys were conducted during October 2012 in SilleRiver, East Siang District, Arunachal Pradesh. Fish samples were collected from the
heap of stones stored by local people. The collected specimens were preserved in 10% formalin and later
transferred to 70% ethanol for preservation. The fish were identified following Ng
(2009) and have been deposited in the Zoological Survey of India (ZSI),
Arunachal Pradesh Regional Centre, Itanagar, Arunachal Pradesh. Measurements using
digital calipers (MitutoyoCorporation, Japan) to the nearest 0.1 mm and expressed as percentage of
standard length (SL) or head length (HL). Counts and measurements were made on the
left side of the specimens following (Ng & Kottelat2001). The number written in
parentheses after a specific fin ray count indicates the number of specimens
examined.
Batasio merianiensis (Chaudhuri,
1913)
(Images 1 & 2)
Macrones merianiensis Chaudhuri, 1913: 253, Pl. 9 (Figs. 1, 1a-b) [type
locality: pond at Mariani Junction, Assam, India, holotype, ZSI F7781/1].
Material examined: ZSI/V/APFS/P-602, 26–27.x.2012, six
specimens, 43.4–57.8 mm SL, Sille River, about
1km upstream from RCC bridge over Sille River, about
10km from Ruksin, East Siang District, Arunachal
Pradesh, India, 27052’38”N & 95018’18”E; coll. Lakpa Tamang.
Description
Head is V-shaped when viewed dorsally and laterally (Image 1), it is
longer than its width and depth, with 4–5 small sensory pores on dorsum
region. Five
distinct large sensory pores present immediately on the posterior region of
lower lip (two pores situated in between the lower lip margin and the origin of
mandibular barbel and one pore at mid line). Two rows of pores
(four in each) along the side of mental region (Fig. 1). Maxillary barbelsare reaching or slightly exceeding posterior orbital margin. Dorsal spine smooth,
no serrations on its anterior or posterior margin. Pectoral fin with 8 (3); 7,i (2) and 7 (1) rays. Tip of adpressed pelvic fin reaching anterior
margin of external genitalia, but not reaching anal-fin origin. Anal fin with iv,10(1); iii,9 (1); iv,8 (2); iv,7,i (1) and iii,7 (1) rays. Caudal fin with i,7,10,i(4) and i,7,9,i (2) rays. A long
slender genital papilla found in two specimens out of six, extending nearer to
base of anal fin, which is a feature present in males. One male was found to be larger (57.8 mm
SL) among all.
Distance between pectoral-fin and pelvic-fin
origin and between dorsal-fin and pelvic-fin origin is equal. Eye diameter
almost equals internarial distance. Pectoral fin slightly
shorter than dorsal fin. Dorsal-fin base equals to anal-fin base.
Coloration in preservative: Body and head faint brownish, darker at snout and occipital region. The
Ventral surface is creamy. Eyes are grayish-white.
Minute dark brown spots almost uniformly distributed all over the body and
head.
Ecological notes: Batasio merianiensis were
found to live in the bottom of clear shallow running water, the river comprised
of pebbles, cobbles of variable colors and sand
particles. The fish were found to
dwell preferably inside the gaps under the heap of stones in stagnant water of
depth about (20–40 cm) in the winter. River bank vegetation consists of
grasses, bushes and trees. Following fishes were also captured along with B. merianiensis:Aborichthys elongatus,Acanthocobitis botia,Amblyceps mangois,Badis singenensis,Chanda nama, Garra annandalei, G. gotyla, Mastacembelus armatus, Pangio pangia, Pseudolaguvia viriosa, Pseudolaguvia sp., Schistura savona. Other species caught from adjacent
area were Balitora brucei,Barilius barna, B. bendelisis, Botia rostrata, Crossocheilus latius, Neolissochilus hexagonolepis, Psilorhynchus balitora, Pethia ticto, and Tor tor.
Catching method: In the present study, we found that some local fishermen and farmers were fishing using semi-traditional fishing
technique locally known as “LIPUM” in the study site. On inquiry, we learnt that this
operation is carried out during the winter season (October–January)
mostly. Medium size stones are deposited nearby river bankin a cylindrical pattern (ca. 15–20 inches high), which is generally left
undisturbed for 3–4 weeks so as to allow fishes to enter inside. A modified mosquito net (cylindrical
shape, top and bottom open) is used to cover the “LIPUM” completely and the
stones are removed from inside the net and fishes are caught. In the study site, 10 LIPUMS or fishing
spots were observed during our survey and found 90% catch frequency of B. merianiensiswhich indicates a normal population distribution of Batasio merianiensis in the study site.
Distribution
Known from the Brahmaputra River drainage in Arunachal Pradesh and
Assam, northeastern India (Fig. 2). The SilleRiver is one of the tributaries of Siang River, which joins the Brahmaputra
River in Assam.
Discussion
Among the other five species of Batasioreported from the Brahmaputra River drainage only B. merianiensisand B. fasciolatus have dark vertical bars on
the head. The present specimens
from upper Brahmaputra River basin fully shares this important character
however, can be easily distinguished from B. fasciolatusin having the adpressed dorsal fin not reaching (vs.
overlapping) the anterior adipose-fin origin and in having larger eye (diameter
20.7–23.3 % HL vs. 16.5–18.8). The dark brown subdistalovoid patch on dorsal fin in the present specimens has close similarities with
the original illustration of the holotype by Chaudhuri (1913: Pl. 9, Fig. 1).
The present specimens shares most of the characters provided in the
Table 1 which are closely related or overlapping particularly on the length of
the predorsal, prepelvic,
dorsal-fin base, dorsal-spine, anal-fin base, pectoral-fin, pectoral-spine,
pelvic-fin, caudal-fin, head, snout, caudal peduncle, nasal-, maxillary-,
inner-, and outer mandibular barbel with B. merianiensis. Other characters include caudal peduncle and head depth, dorsal to
adipose- and interorbital distance, and eye
diameter. In addition, the meristic
feature in case of dorsal-, pelvic-fin rays and number
of serrae on posterior margin of pectoral spine is
exactly the same with negligible variations seen in pectoral-, anal- and
caudal-fin rays (Table 2).
However, few morphological variations were observed on the following
characters: by having a longer preanal (70.4–73.4
vs. 66.3–68.2 % SL); a longer prepectoral(25.1–29.3 vs. 21.4–25.7 % SL); a longer adipose-fin base
(22.0–27.6 vs. 16.9–22.2 % SL); a shorter post-adipose distance
(11.6–13.4 vs.13.4–15.5% SL); a deeper body at anus (depth
18.3–20.8 vs.15.2–18.4% SL) and a broader head (width
17.6–20.0 vs.13.5–16.2 % HL).
Conclusion
The extensive use of the semi-traditional fishing technique would
obviously affect the population of Batasio merianiensis in the study site. Besides, mosquito nets are more
hazardous as it holds up almost all sizes of fishes because of minute
meshes. Thus such technique
employed would obviously affect the natural growth of the population of the
fish. As far as the preferred
microhabitat of the fish is concerned, the situation would be worsened if
non-conventional method of fishing such as the use of chemicals and electricityare employed as previously reported by Tamang & Chaudhry(2012). Keeping in mind the
moderate population size of the fish, its preferred micro habitats and excessive
usage of the semi-traditional fishing method, there is an urgency to take
necessary measures for the conservation of this poorly known species,
continuous practicing of this fishing technique otherwise may eventually wipeout the species from the present study area.
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