Snake Heads or Murrels or Channids

Lot 10: Field Identification tips and segregation of Channa sp. (Snake Heads) [Lot 10] from Doon Valley and fresh market catches.

Sort out the fish which have long dorsal and anal fins and large scales on the body extending up to head:

……. place them labeled as Snake Heads or Murrels or Channids.

The sorting of some fishes in the field / fresh market catches was made on the basis of long dorsal and anal fins and large scales on the body extending up to head. They were placed under ‘Lot 10’, tentatively labeled as Snake Heads or Murrels or Channids.

 

Snake Heads or Murrels or Channids
Habitat preferences by Channa sp.:

These fishes have most-preferred dwelling sites in the form of swampy, marshy, almost stagnant pools (as seen in photographs ahead) created amidst river stretches, particularly in post-monsoon months. Most of the time, they rest along the bottom among the submerged shoots and roots of aquatic submerged or marginal emergent vegetation.

 

Photograhes of Habitat preferences by Channa (Snake heads or Murrels) sp. from Doon Valley, Uttarakhand, IndiaHabitat preferences by Channa (Snake heads or Murrels) sp.: Song River (Eastern Doon): A shallow weedy channel.Song River (Eastern Doon): A shallow weedy channel.

Habitat preferences by Channa (Snake heads or Murrels) sp.: Song River (Eastern Doon): An isolated weedy pool.Song River (Eastern Doon): An isolated weedy pool.

Habitat preferences by Channa (Snake heads or Murrels) sp.Suswa River (Eastern Doon): An isolated weedy pool, showing growth of Eichhornia and submerged Hydrilla.

Habitat preferences by Channa (Snake heads or Murrels) sp.: Suswa River (Eastern Doon): An isolated weedy pool, showing growth of Leersia grass, Eichhornia and submerged Hydrilla. Suswa River (Eastern Doon): An isolated weedy pool, showing growth of Leersia grass, Eichhornia and submerged Hydrilla.

Habitat preferences by Channa (Snake heads or Murrels) sp.: Suswa River (Eastern Doon): An isolated weedy pool, fishing action by dragging.Suswa River (Eastern Doon): An isolated weedy pool, fishing action by dragging.

Habitat preferences by Channa (Snake heads or Murrels) sp. Suswa River (Eastern Doon): An isolated weedy pool, fishing action by dragging.

Suswa River (Eastern Doon): An isolated weedy pool, fishing action by dragging.

Habitat preferences by Channa (Snake heads or Murrels) sp.: Suswa River (Eastern Doon): Showing covering of algal mats, Pistia and Spirodella sp.Suswa River (Eastern Doon): Showing covering of algal mats, Pistia and Spirodella sp.

Habitat preferences by Channa (Snake heads or Murrels) sp. Asan River Bed (Western Doon) with weedy (Rorippa and Leersia sp.) growth.Asan River Bed (Western Doon) with weedy (Rorippa and Leersia sp.) growth.

Song River (Eastern Doon): A freshly caught Snake Head (Channa sp.)Song River (Eastern Doon): A freshly caught Snake Head (Channa sp.)

Asan River (Western Doon): A shallow, slow running side channel with aquatic growth, a favourite dwelling ground for Channa sp. and also serpentine Mastacembelus sp. (Lot 9), Clarias sp. (Lot 11), Cobitids (Lot 14) etc.

Species segregation:

The samples put under Lot 10, labeled as Snake Heads or Channids or Murrels [Suborder: Channoidei, Family : Channidae] can be segregated, in order of abundance, into 3 species viz., Channa punctatus > C. gachua > C. marulius.

Alike in shape, all are with long dorsal and anal fins, scales reaching up to head (head appearing like that of a snake). They can be broadly isolated on the basis of their diagnostic colour patterns. For the sake of convenience some meristics, shape of the isthmus, big scale on the lower jaw and ventral cephalic sensory pores are also included as other segregating characteristics.

  • Largest in size (30.4 – 30.8 cm) amongst rest of the two. Isthmus ‘V’- shaped. A big scale just behind the jaw articulation present ventrally. Ventral cephalic sensory pores arranged in groups. Colour shade variable according to the habitat; from lighter to darker according to the penetration intensity of light; darker from shaded weedy, forested niches. Dark brownish to blackish or greeish-grey dorsally, paler ventrally. The dark shaded individuals show tiger-like dark bands descending on both the flanks from base of long dorsal fin (light coloured individuals does’nt show tiger-like banding). 5 – 6 cloudy patches (flowery appearance), having white edged scales present along the flanks. A well marked ocellus with orange or lighter boundary present at the upper basal part of the caudal fin. Scales on the head larger. Dorsal fin rays 45 – 55, Anal 28 – 36 and Lateral line scales 60 – 70.

……………………….. Channa marulius

PHOTOGRAPHS OF Channa marulius

Channa marulius: Live, dark-coloured specimens (from Suswa River, Rajaji National Park, Eastern Doon) in a glass trough. Fascinating to watch tiger-like dark bands descending on both the flanks from base of long dorsal fin.

Channa marulius: Live specimen in a glass trough. The dark shaded individuals show tiger-like dark bands (yellow arrows) descending on the flanks from base of long dorsal fin. Diagnostic 5 – 6 cloudy patches (flowery appearance), having white edged scales, present along the flanks (red arrows). A well marked ocellus with orange or lighter boundary present at the upper basal part of the caudal fin (blue arrow).Channa marulius: Live specimen in a glass trough. The dark shaded individuals show tiger-like dark bands (yellow arrows) descending on the flanks from base of long dorsal fin. Diagnostic 5 – 6 cloudy patches (flowery appearance), having white edged scales, present along the flanks (red arrows). A well marked ocellus with orange or lighter boundary present at the upper basal part of the caudal fin (blue arrow).

Channa marulius: Lateral view magnified. This dark-coloured specimen does’nt have tiger-like blank bands on the flanks. 5 – 6 cloudy patches (flowery appearance), having white edged scales present along the flanks (yellow arrows). Channa marulius: Lateral view magnified. This dark-coloured specimen does’nt have tiger-like blank bands on the flanks. 5 – 6 cloudy patches (flowery appearance), having white edged scales present along the flanks (yellow arrows).

Channa marulius: Caudal peduncle and caudal fin region magnified. Mark the presence of an ocellus with orange or lighter boundary at the upper basal part of the caudal fin (yellow arrow).Channa marulius: Caudal peduncle and caudal fin region magnified. Mark the presence of an ocellus with orange or lighter boundary at the upper basal part of the caudal fin (yellow arrow).

Channa marulius: Light coloured fresh specimens (see two different shades) being sold in local fish market (Banda, UP, India)[16.12.2019]. Channa marulius: Light coloured fresh specimens (see two different shades) being sold in local fish market (Banda, UP, India)[16.12.2019].

Channa marulius: Head and isthmus region magnified ventrally. Mark ‘V’- shaped Isthmus (black arrow) and presence of a big scale behind articulation of jaws (blue arrow). Ventral cephalic sensory pores arranged in groups (red arrows).Channa marulius: Head and isthmus region magnified ventrally. Mark ‘V’- shaped Isthmus (black arrow) and presence of a big scale behind articulation of jaws (blue arrow). Ventral cephalic sensory pores arranged in groups (red arrows).

Live Channa marulius, being sold in fish market[16.12.2019] at Banda (UP). The ocellus on the upper base of caudal fin is not clearly visible. Also mark some caudal fin rays longer than the others.
  • Size 12.0 – 14.0 cm. Isthmus ‘U’- shaped. A big scale present on the lower jaw (more anteriorly to the ariculation of jaws). Ventral cephalic sensory pores present singly. Body dark green along the back, turning olive-green on the flanks; pale to yellowish ventrally. 6 – 7 dark patches descend down from the dorsum to lateral line, alternating with similar 7 – 8 patches below lateral line, often giving ‘ < ’ – shaped appearance. Lower lateral half of the head and sides mottled with dark spots. A vertical yellowish band can be seen at the base of the caudal fin. A prominent black band originates at the tip of snout and after passing through the eye, ends at the upper edge of the operculum. Dorsal, anal and caudal fins edged yellow or white. Dorsal 20 – 30, Anal 21 – 23 and Lateral line scales 37 – 40.

………………………….. Channa punctatus

PHOTOGRAPHS OF Channa punctatus

Channa punctatus: Assemblage of live individuals in a basket being sold in local fish market at Banda (UP, India) [16.12.2019]. Mark dark patches on the flanks (red arrow) and a yellow vertical streak (yellow arrow) at the base of caudal fin.Channa punctatus: Assemblage of live individuals in a basket being sold in local fish market at Banda (UP, India) [16.12.2019]. Mark dark patches on the flanks (red arrow) and a yellow vertical streak (yellow arrow) at the base of caudal fin.

Channa punctatus: Lateral view. Mark dark patches on the flanks (red arrows) and a yellow vertical streak (yellow arrow) at the base of caudal fin. Lower lateral half of the head and sides mottled with dark spots (blue arrows). Dorsal, anal and caudal fins edged yellow or white.Channa punctatus: Lateral view. Mark dark patches on the flanks (red arrows) and a yellow vertical streak (yellow arrow) at the base of caudal fin. Lower lateral half of the head and sides mottled with dark spots (blue arrows). Dorsal, anal and caudal fins edged yellow or white.

Channa punctatus: Anterior region magnified. Lower lateral half of the head and sides mottled with dark spots (blue arrows). Sometimes a prominent black band originates at the tip of snout and after passing through the eye orbit, ends at the upper edge of the operculum (yellow arrows).Channa punctatus: Anterior region magnified. Lower lateral half of the head and sides mottled with dark spots (blue arrows). Sometimes a prominent black band originates at the tip of snout and after passing through the eye orbit, ends at the upper edge of the operculum (yellow arrows).

Channa punctatus: Head and isthmus region magnified ventrally. Mark ‘U’- shaped Isthmus (black arrow) and presence of a big scale (blue arrow) on the lower jaw (more anteriorly to the ariculation of jaws). Ventral cephalic sensory pores arranged singly (red arrows).Channa punctatus: Head and isthmus region magnified ventrally. Mark ‘U’- shaped Isthmus (black arrow) and presence of a big scale (blue arrow) on the lower jaw (more anteriorly to the ariculation of jaws). Ventral cephalic sensory pores arranged singly (red arrows).

  • Size 3.5 – 12.5 cm. Isthmus U’- shaped. A big scale present on the lower jaw (more anteriorly to the ariculation of jaws). Dark green or purplish black along the back, lighter on the sides. ‘<’ – shaped, sometimes undistinguishable bands present on the flanks. Dorsal, anal and caudal coloured dark grey and banded; dorsal and anal edged bright orange. Diagnostically the pectorals are with blue-black base and similarly coloured 3 – 4 transverse bars, separated by orangish interspaces. Tubular nostrils (present in other three species, too) more pronounced and projecting beyond the edge of the upper jaw. Dorsal 32 – 37, Anal 21 – 23 and Lateral line scales 40 – 45. Pelvic fins shortest.

…………………….. Channa gachua

PHOTOGRAPHS OF Channa gachua

Channa gachua: Lateral view. Showing banded flanks and pectoral fins, more pronounced tubular nostril and shorter pelvic fins.Channa gachua: Lateral view. Showing banded flanks and pectoral fins, more pronounced tubular nostril and shorter pelvic fins.

Channa gachua: Lateral view. Showing the pectorals with blue-black base and similarly coloured 3 – 4 transverse bars (yellow arrows), separated by orangish interspaces. Tubular nostrils (present in other species, too) more pronounced (blue arrow), projecting beyond the edge of the upper jaw.Channa gachua: Lateral view. Showing the pectorals with blue-black base and similarly coloured 3 – 4 transverse bars (yellow arrows), separated by orangish interspaces. Tubular nostrils (present in other species, too) more pronounced (blue arrow), projecting beyond the edge of the upper jaw.

Channa gachua: Head and isthmus region magnified ventrally. Mark ‘U’- shaped Isthmus (yellow arrow) and presence of a big scale (blue arrow) on the lower jaw (more anteriorly to the ariculation of jaws). Ventral cephalic sensory pores arranged singly (red arrows). Pelvic fins shorter (orange arrow).Channa gachua: Head and isthmus region magnified ventrally. Mark ‘U’- shaped Isthmus (yellow arrow) and presence of a big scale (blue arrow) on the lower jaw (more anteriorly to the ariculation of jaws). Ventral cephalic sensory pores arranged singly (red arrows). Pelvic fins shorter (orange arrow).

JUVENILES OF Channa sp.

The juveniles of all the Channa species are characterized by a distinct golden yellow band along the flanks as well as mid-dorsally, from behind the eye to the base of the caudal fin (found to be persisting even up to about 9.5 cm, as observed in some specimens of Channa punctatus).

Additionally, the youngs of Channa gachua possess an ocellus at the hinder edge of the dorsal fin.

Curiously enough, the young ones of C. gachua were found in numbers, hiding amidst stones and pebbles with trickling stream of subterranean water [As also found in case of a catfish Amblyceps mangois dealt under Lot 11].

PHOTOGRAPHS OF Channa juveniles

Channa punctatus: Live specimen with juveniles. The presence of fragments of Algal Mats give an indication of hiding places for the juveniles.Channa punctatus: Live specimen with juveniles. The presence of fragments of Algal Mats give an indication of hiding places for the juveniles.

Juveniles of Channa sp. Mark the diagnostic golden yellow band along the dorsum and flanks. The presence of Algal Mats give an indication of hiding places for the juveniles.Juveniles of Channa sp. Mark the diagnostic golden yellow band along the dorsum and flanks. The presence of Algal Mats give an indication of hiding places for the juveniles.

One juvenile of Channa punctatus (Lateral view): Mark the diagnostic golden yellow band along the flank.One juvenile of Channa punctatus (Lateral view): Mark the diagnostic golden yellow band along the flank.

Channa gachua: Juvenile with a black ocellus (incidently two in this specimen) at the hinder end of dorsal fin (yellow arr

Channa gachua: Juvenile with a black ocellus (incidently two in this specimen) at the hinder end of dorsal fin (yellow arr

Live juveniles of Channa sp., showing swimming and bubble- releasing activity.

PARASITIC INFESTATION IN Channa sp.

A CURIOUS FIELD OBSERVATION

This field observation is important in the sense that while doing collections in the field, other related aspects, if revealed in the field, should be recorded textually or photographically. The example of parasitic infestation presented here is additionally important for the budding Ichthyologists.

Some specimens of Channa punctatus, collected from a weedy channel of Asan River (Western Doon) were found infested with ‘Fish Louse’ [Argulus sp., Phylum: Arthropoda; Subphylum: Crustacea; Class: Maxillopoda; Subclass: Branchiura; Order:Arguloida; Family: Argulidae], clinging to the pectoral fins (See photograph).

Argulus is one of the most widespread Crustacean Ectoparasite of freshwater Fishes of the world. They are greenish-yellow, semitransparent and have two disc-shaped suckers on the ventral surface, used to attach themselves to the fish.

PHOTOGRAPHS OF ‘Fish Louse’ [Argulus sp.,]

PHOTOGRAPHS OF ‘Fish Louse’ [Argulus sp.,]

Channa punctatus: Showing infestation of fish louse (Argulus sp.; Phylum: Arthropoda; Subphylum: Crustacea; Class: Maxillopoda; Subclass: Branchiura; Order:Arguloida; Family: Argulidae) on the pectoral fin (yellow arrows); one detached individual magnified in another photograph.

Channa punctatus: Showing infestation of fish louse (Argulus sp.; Phylum: Arthropoda; Subphylum: Crustacea; Class: Maxillopoda; Subclass: Branchiura; Order:Arguloida; Family: Argulidae) on the pectoral fin; one detached individual magnified in another photograph.