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Mitochondrial DNA typing of 52 fish eggs collected in Sendai Bay and off Johban revealed ten haplotypes of the 225–251 bp region of 16S ribosomal DNA. Comparing with known sequences of fishes, we identified them as Trachurus japonicus (Carangidae), Pagrus major, Evynnis japonica (Sparidae), Paralichthys olivaceus, Pseudorhombus sp. (Paralichthidae), Pennahia argentata (Sciaenidae) and Platycephalus sp. (Platycephalidae). The occurrence of Trachurus japonicus and sparid eggs in the study area indicates significant extensions to the ranges of their spawning sites northward. Our method is useful for identifying fish eggs that are difficult to diagnose by morphology, and to uncover cryptic fish egg assemblages in the field.

Cephalic lateral line canals in two pleuronectiforms, Pseudorhombus pentophthalmus (Paralichthyidae) and Engyprosopon grandisquama (Bothidae), were studied and their homologies between the ocular and blind sides assessed on the basis of position and innervation patterns. A blind side canal, comprising small ossicles in a line lateral to the upper eye floor, was confirmed as the infraorbital line because the canal was not innervated by a ramus associated with the upper nasal (i.e., the superficial ophthalmic ramus innervating the supraorbital line). Consequently, the ramus innervating the canal was identified as the buccal ramus (associated with the infraorbital line). The blind side frontal forming the posterior half of the upper eye floor was identified as that part bearing the anteriormost otic canal in the ocular side, hypertrophy of the blind side component being evident. The supraorbital line of the blind side was represented by the upper nasal only in E.grandisquama.