Lacustricola chobensis (Fowler, 1935)

Family:  Procatopodidae (African lampeyes), subfamily: Procatopodinae
Max. size:  2.4 cm SL (male/unsexed)
Environment:  pelagic; freshwater
Distribution:  Africa: widespread in the Okavango, Cuando, upper and lower Zambezi Rivers, a region comprising southern Angola, northern Botswana, northeastern Namibia, southern tip of Malawi, southern Mozambique, and northern Zambia (Ref. 123968).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 6-8; Anal spines: 0-0; Anal soft rays: 10-13; Vertebrae: 24-26. Diagnosis: Lacustricola chobensis is distinguished from L. centralis, L. jobaerti, L. johnstoni, L. jubbi, L. katangae, L. macrurus, L. matthesi, L. mediolateralis, L. moeruensis, L. myaposae, L. nigrolateralis, and L. stiassnyae by the possession of banded dorsal, anal, and caudal fins in males, a conspicuous reticulate pattern on scale margins, and also by the possession of a pointed premaxilla ascending process, in which the premaxilla medial surface is slightly convex (Ref. 123968). It is distinguished from L. hutereaui by the possession of 10-13 anal-fin rays vs. 14-15; first dorsal-fin ray inserted in a vertical to the fourth or fifth anal-fin rays, vs. sixth anal-fin ray; first dorsal-fin proximal radial between 11th-12th vertebral neural spine, vs. 13th; absence of maxilla ventral sharp process, vs. presence; retroarticular about the same size as anguloarticular ventral process, vs. shorter; posteroventral extension on lachrymal, vs. rectangular, without posteroventral extension; infraorbital canal anterior portion open, with three neuromasts, vs. closed, with four pores; mandibular canal open, with two small neuromasts, vs. closed, with four pores; head neuromasts placed in shallow grooves or in the same level as head surface, vs. in deep grooves; posttemporal ventral arm not ossified, vs. ossified; cleithrum posterodorsal flap rounded, vs. sinous; and by hypural plate completely fused, vs. with a small gap, rarely fused (Ref. 123968). It is distinguished from L. petnehazyi by the presence of 10-12 anal-fin rays, vs. 14-16; first dorsal-fin ray inserted in a vertical to fourth or fifth anal-fin rays, vs. sixth to eight anal-fin rays; 22-24 scales on longitudinal line, mode 23, vs. 24-27, mode 26; 6-8 dorsal-fin rays, mode 7, vs. 8-9 dorsal-fin rays, mode 9 (Ref. 123968). It is distinguished from L. pygmaeus by the possession of 21-24 caudal-fin rays, vs. 26-30; an elliptical caudal fin in males, vs. rounded; chromatophores along whole mid-body line of flank, forming a conspicuous line, vs. inconspicuous; 6-8 dorsal-fin rays, vs. 10-12; first dorsal-fin ray inserted in a vertical to the fourth or fifth anal-fin rays, vs. second and third anal-fin ray; and by the absence of a concavity on quadrate posterior margin, vs. presence (Ref. 123968).

Description: Dorsal profile of body slightly convex from snout tip to dorsal-fin origin; slightly concave from dorsal-fin origin to end of caudal peduncle; ventral profile convex from lower jaw to end of anal-fin base; nearly straight on caudal peduncle; anterior portion of body laterally compressed, becoming more compressed behind anal-fin origin (Ref. 123968). In males, dorsal fin rounded and slightly more elongated than in females; its origin in vertical between 4th and 5th anal-fin rays; anal fin rounded and slightly elongated in males; pelvic fin in males reaching between urogenital papilla aperture and base of first anal-fin ray; in females, pelvic fin shorter than in males, tip reaching region just before urogenital opening; caudal fin elliptical in both sexes; pectoral fin elliptical in both males and females, its posterior margin reaching vertical just behind pelvic-fin base; in both males and females, dorsal-fin rays 6-8; anal-fin rays 10-13; caudal-fin rays 21-24; pectoral-fin rays 11-14; pelvic-fin rays 6 (Ref. 123968). Frontal squamation G-patterned; head neuromasts placed in shallow grooves or on same level as head surface; cephalic lateral-line system: anterior portion of supraorbital sensory canal open, with three neuromasts, anteriormost one anteriorly displaced from other two; posterior portion open, with three exposed neuromats; anterior infra-orbital canal open, with three exposed neuromasts; median portion of infra-orbital region with series of 9-11 minute neuromasts; posterior infra-orbital canal closed, with two pores; preopercular canal closed in both dorsal and ventral portions with 5-6 pores; mandibular canal represented by two neuromasts, one in vertical through corner of mouth and other anteriorly positioned in the lower jaw ventral portion (Ref. 123968). Longitudinal series of scales 22-24; transverse series of scales 6; circumpeduncular scales 10; predorsal scales 12-14 (Ref. 123968). Mesethmoid and vomer absent; frontal anterior margin slightly extends anteriorly between nasals; parasphenoid medial process short, not contacting pterosphenoid; anterior margin rounded; lateral ethmoid overlaps anterior portion of parasphenoid; supraoccipital posterior process long, reaching first vertebra; lachrymal with posteroventral extension; premaxillary and dentary teeth well developed, conical; outer row with larger well-spaced teeth; retroarticular triangular or subtriangular, about same depth and length to anguloarticular ventral arm; dentary deep; dorsal process of maxilla broad, overlapping premaxilla ascending process; ventral process greatly reduced, consisting of rounded ventromedial bulge; ventral arm of maxilla broad, laterally expanded; premaxilla ascending process medial surface with convex profile; entopterygoid posterior portion and symplectic keel deep; opercle triangular, anterodorsal process present; anterior process of anterior ceratohyal not extending ventrally to ventral hypohyal; urohyal ventral margin straight to slightly concave; first and second basibranchials lateral bone flanges unexpanded; basihyal cartilaginous portion shorter than osseous portion; fourth ceratobranchial, anterior third portion with teeth; second pharyngobranchial plate with teeth; base of first epibranchial broad, more than three times width of anterior portion; supracleithrum rounded; posttemporal rodlike, ventral arm absent; cleithrum bony flange not covering scapula foramen; cleithrum posterodorsal flap rounded; ventral postcleithrum slender, similar in width to adjacent first pleural rib; basipterygium posterior process shorter than medial process; anal-fin proximal radials about same length and parallel to each other; hypurals completely fused; parhypural proximal end overlapping preural centrum; total vertebrae 24-26, precaudal 1012 and caudal 13-15; first proximal radial of dorsal fin between neural spine of vertebrae 11 and 12; first proximal radial of anal fin between pleural rib of vertebrae 9 and 11 (Ref. 123968). Gillrakers on first branchial arch 7-9; branchiostegal rays 5 (Ref. 123968).

Colouration: Colouration in alcohol: overall colouration of body pale yellowish brown with conspicuous dark brown reticulate pattern along margins of flank scales; anterior portion of flank darker; dorsal portion of body and anterior region of flank dark brown, densely pigmented; ventral surface scarcely pigmented; brown chromatophores along whole mid-body line of flank, forming conspicuous line; head overall colouration yellowish brown; brown chromatophores on dorsum of head, lower jaw, and preorbital region, forming distinct darker region; iris silver, darker close to pupil; dark pigment concentrated on dorsal margin of eye; all fins hyaline in females, with melanophores sparsely concentrated only on base of anal-, dorsal-, and caudal-fin membranes; melanophores forming conspicuous transversal bands on male dorsal and anal fins, and faint brown margin in both fins; caudal fin with three to five conspicuous vertical bands, and faint brown margin; pelvic fin with melanophores sparsely concentrated on fin membrane; pectoral fin hyaline; female urogenital opening pocket scales with dark brown chromatophores (Ref. 123968). Colouration in life of males: side of body bright green, mainly in posterior head region and flank anterior region, with conspicuous dark brown reticulate pattern along scale margins, slightly thicker on each scale anterior margin; dorsum yellowish green; ventral surface white between head and region anterior to pelvic-fin origin; grey between pelvic fin and caudal peduncle; side of head predominantly bluish green, dorsal portion yellowish brown, postorbital region with distinct bright green blotch; iris dark grey, light yellow close to pupil; eye bright bluish green on dorsal portion; lower jaw and preorbital region dark brown-grey, forming distinct horizontal band; pectoral fin hyaline; all other fins orange-yellow with dark brown dots arranged as distinct bands; dorsal and anal fins with transverse bands; and caudal fin with three to five rows of transverse bands; anal, dorsal, and caudal fins with dark brown to black marginal band, broader in caudal fin (Ref. 123968). Colouration in life of females: side of body pale grey, with conspicuous dark brown reticulate pattern along scale margins; anterior portion of flank darker; bluish green iridescent blotch on region from pectoral-fin insertion into vertical to pelvic fin; dorsum grey-brown; venter white between head and region just anterior to urogenital opening; bright purple-blue between urogenital opening and end of anal-fin base; brownish grey from end of the anal-fin base to caudal peduncle; scales around urogenital opening covered with dark chromatophores; side of head predominantly dark brown, ventral portion white, dorsal portion dark brown, postorbital region with distinct light blue bright blotch; iris dark grey, light yellow close to pupil; eye bright silver-green on dorsal portion; lower jaw and preorbital region dark brown-grey, forming distinct stripe; pectoral and pelvic fins hyaline; dorsal fin orange, distal margin hyaline; anal fin hyaline, with distinct orange blotch on anterior portion; caudal fin hyaline with light orange colouration on ray insertions (Ref. 123968).

Biology:  Found in swampy and riverine environments close to marginal vegetation (Ref. 123968).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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