Environmental Engineering Reference
In-Depth Information
found
in
association
with
running
beetles) live among aquatic vegetation along the
edges of ponds, lakes, streams or creeks. They
are best identifi ed by the large coxal plates cov-
ering the base of the hind legs and abdomen.
Their tarsi have two claws. They are omnivores
found in the vegetation of pools. They are small
beetles with their size at maturity of about
2-6 mm. Regimbart (
1882
) recorded the fi rst
Indian species
Haliplus angustifrons
from
Bihar. So far fi ve species are recorded under the
genus
Haliplus
from India.
The hydrophilids (water scavenger beetles)
are predominant in rivers and streams. They are
characterized by their short-clubbed antennae
that generally remain concealed beneath the head
and long maxillary palps resembling antennae
like Dytiscidae; they also make contact with the
surface water fi lm with the anterior edge of their
body, but unlike the former, their hind legs move
alternately while swimming and they are not very
good swimmers. Beetles belonging to the family
Elmidae (riffl e beetles) live in running water.
Some breathe underwater using an air fi lm
trapped by hairs as a physical gill, mostly aquatic
in both adult and larval stages. This is a family of
small beetles 2-5 mm long. They have punctured
elytra and raised lines on the thorax. The riffl e
beetles usually have fi liform antennae that are
much longer than the head. Their tarsi are dis-
tinctly fi ve segmented and have 5-6 abdominal
segments. They are underwater crawlers and do
not swim; therefore, they have no swimming
hairs on their hind legs.
The inventory comprises of 31 species accom-
modated under 20 genera and four families.
Under each species, citation for original descrip-
tion and other accompanying work necessary to
undertake the taxon is given.
1. Family: Dytiscidae
The members of this family have adapted per-
fectly well to aquatic life. All adults and larvae
are aquatic. These beetles are commonly known
as “predacious diving beetles” as they feed vig-
orously upon almost all invertebrates and fi sh
eggs and fry. Both adults and larvae are preda-
ceous and attack a wide variety of small aquatic
organisms. These beetles generally occupy clean
water -
Elmidae
A checklist of Gerromorpha (Hemiptera)
from India (Thirumalai
2002
) and a synoptic list
of Nepomorpha (Hemiptera: Heteroptera) from
India (Thirumalai
2007
) are also given in ZSI
website
www.zsi.gov.in
.
An attempt has been
made to update the checklist of aquatic
Coleoptera. Of the 18 families of aquatic
Coleoptera known from the world representa-
tive of fi ve families namely Dytiscidae,
Gyrinidae, Hydrophilidae, Haliplidae, Elmidae,
Dryopidae and Notoridae are chiefl y repre-
sented in India. The checklist of aquatic
Coleoptera from India presented here includes
fi ve families and lists a total of 396 species
under fi ve families. The earlier knowledge and
scientifi c contribution on aquatic beetles
(Vazirani
1968
,
1970
and
1984
) are noteworthy
to understand the present fauna. The major stud-
ies on aquatic Coleoptera also include the works
of Jach and Balke (
2008
), Mukhopadhyay and
Ghosh (
2003
) and Biswas and Mukhopadhyay
(
1995
). The members of the family Dytiscidae
(predacious diving beetles) feed vigorously
upon almost all invertebrates and fi sh eggs and
fry. These beetles generally occupy clean and
fresh macrophytic leaves near the bottom along
the littoral zone. They are active swimmers and
swift divers. Adult dytiscids range from 1.4 to
3.8 mm in length. Although most species are
small to medium sized, some adults can attain a
length of 35 mm. The hind coxae are very large
and the second and third legs are widely sepa-
rated. The antennae are very long and threadlike
with 11 segments. The members of the family
Gyrinidae (whirligig beetles) are found in fresh-
water ponds, lakes, open fl owing streams, etc.
The fi rst abdominal sternite is divided by hind
coxae (suborder Adephaga); short, clubbed
antennae; and seemingly 2 pairs of eyes. The
forelegs are long and thin; the middle and hind
legs are short and paddle-like, not extending
beyond the margin of the abdomen (only front
legs visible in dorsal view); the body is elongate
oval and fl attened, usually 3 to 15 mm in length.
The members of Haliplidae (crawling water
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