Description and Comparison of the Canals and Canal Branching Pattern of the Lateral Line Canal System of Dorosoma petenense (Günther) [Clupeomorpha: Clupeoidei]
The lateral line canals, canal neuromasts, dermal canal carrying bones and scales, and canal branches of Dorosoma petenense are described and compared with those of clupeids Dorosoma cepedianum, Brevoortia patronus, Brevoortia tyrannus, Caspialosa pontica, Chirocentrus dorab, Clupea harengus, Clupeonella cultriventris, and Sardina pilchardus. The first trunk lateral line canal carrying scale is narrower than the second in Denticeps clupeoides, Dorosoma petenense, Dorosoma cepedianum, and Sardina pilchardus. Although the clupeoid lateral line canal system is complex, information from its branching pattern, with or without information from other systems of the body, could provide significant justification for a fully resolved phylogeny of clupeoids.
(A) Left lateral view of disarticulated dermal canal bearing bones and scales in a 120.0 mm SL specimen and the shaded portions of the lateral line canal system they enclose: A, anguloarticular; D, dentary; DP, pterotic; ES, extrascapular; ESC, extrascapular canal; F, frontal; IO 1–6, infraorbital bones 1–6; IOC, infraorbital canal; MTC, main trunk canal; N, nasal; P, preopercle; PA, parietal; PC, postcleithrum; PMC, preoperculo-mandibular canal; RL, recessus lateralis; S, sphenotic; SC, supracleithrum; SOC, supraorbital canal; TS 1, trunk scale 1; TS 2, trunk scale 2. Increment = 4.0 mm. (B) Left lateral view of main trunk canal scales TS 1 trunk scale 1 and TS 2 trunk scale 2 and their shaded main trunk canal enclosing portions: U, dorsally opened canal enclosure; V, ventrally opened canal enclosure. Increment = 1.0 mm.
Left lateral view of the topography of the canals, neuromasts, pores, and pored branches of the lateral line canal system in a 32.0 mm SL specimen. Canals: ATC, accessory temporal canal; EC, ethmoid canal; ESC, extrascapular canal; IOC, infraorbital canal; MTC, main trunk canal; OC, occipital commissure; PMC, preoperculo-mandibular canal; SOC, supraorbital canal. Neuromasts: a through j'. Shading represents the area of the canals and neuromasts enclosed by enclosing components of the lateral line canal carrying bones and scales. The bony enclosures are identified, not unlike in Figure 1, for the bones and scales which contain them: A, anguloarticular; D, dentary; ES, extrascapular; F, frontal; IO 1–6, infraorbital bones 1–6; N, nasal; P, preopercle; PA, parietal; PC, postcleithrum; RL, recessus lateralis enclosed by pterotic and sphenotic; SC, supracleithrum; TS 1, trunk scale 1; TS 2, trunk scale 2. Numerals 1, 2, 4, 5, 7–10, 12, 13, 20, 22, 23, 24, 28, 29, 30, 31–34, 46, 50, 53, 54, 55, 59, 6, 62 identify canal branches in Dorosoma cepedianum hypothesized as homologues of branches present in Dorosoma petenense. Increment = 5.0 mm.