Branchial structures in the Gasterosteiformes were examined osteologically and myologically. Descriptions and illustrations are given for representatives of all families. The absence of a toothplate fused to epibranchial 3 and the presence of adductores 1-3 are proposed as putative synapomorphies of the order. Despite intensive reduction and loss of bones, the muscles tended to remain, their insertions migrating elsewhere. Recti ventrales externi and interni are proposed as new muscle terminology, one or both muscles occurring in aulostomids, fistulariids, pegasids, solenostomids, and syngnathids. Origins of the levatores externi and interni were particularly variable owing to the upward migration of the adductores hyomandibulae and operculi. Indostomids are hypothesized as nonsyngnathoid gasterosteiforms, based on myological characters. The primitive nature of "syngnathoid" macroramphosids and centriscids is established and their phylogenetic positions are discussed.
The cranial osteology and myology in the ateleopodiform Ateleopus japonicus were studied. Many free bony ossicles constitute the cephalic lateral line canals and are separated from the neurocranial roof by thick gelatinous tissue. The preoperculomandibular canal is unique in having a direct connection with the infraorbital canal owing to strong reduction in the size of the preoperculum. The neurocranium is largely cartilaginous, with 6 chondrocranial and 1 dermal element being absent (or not undergoing ossification). The left and right frontals are separated by a deep groove into which a long, mobile rostral cartilage is deeply inserted. Five pairs of cartilages, including 2 pairs of menisci, are associated with the ethmoid region, allowing premaxillary protrusion without involving maxillary rotation. The levator operculi is well developed and likely generates the primary force for depressing the lower jaw. The large interhyal is tightly attached to the entire ventral margin of the operculum, and the two elements appear to function as a single unit in mouth opening. The oral cavity is large because of the posterior position of the branchial arches [the last (5th) arch is situated below the 3rd vertebra]. In pelagic individuals the head is flat with a terminal mouth and straight parasphenoid shaft, whereas in small, benthopelagic individuals the head is rounded with an inferior mouth and bent parasphenoid shaft. "Bending" of the parasphenoid with a dorsally elevated apex is considered the result of the posterior migration of the mouth during the habitat shift. Ateleopodiform characters are discussed phylogenetically and the deep insertion of the rostral cartilage into an open space in the ethmoid region is suggested as a synapomorphy of the order and Lampridiformes. head and inferior mouth, resulting in the "jellynose" condition. Observations on newly settled individuals revealed that metamorphic mouth migration, involving bending of the parasphenoid shaft, results in the latter condition.
Materials and MethodsSpecimens of Ateleopus japonicus for examination were obtained from commercial catches landed by bottom trawlers at fishing ports along Tosa Bay, southern Japan, and are deposited in the Laboratory of Marine Biology, Faculty of Science, Kochi University (BSKU; see below for specimen catalogue numbers). Two pelagic HUMZ [Laboratory of Marine Biology and Biodiversity (Systematic Ichthyology), Hokkaido University] specimens were also examined [see Amaoka and Kobayashi (2003) for collection data]. Osteological examinations were made on specimens cleared and double stained following the method of Potthoff (1984). BSKU 62372-62388, BSKU 75189-75191, 20 specimens, 220-470 mm SL: standard length, HUMZ 185291-185292, 2 specimens, 185-258 mm SL.
IchthyologicalResearch
Satyrichtltys rugosus (Fowler, 1943) was established with no comparison to other peristediid searobins. Our examinatton of types and other material of both S, rugosus and S. clavitopis (Fowler, 1938) has clarified that S. rugosits represents postlarvae and juveniles of the latter speeies. We therefore regard S, rugosus as a junior synonym of S, clavilapis and comment on its ontogenetic changes in morphology,
A single specimen of the rare moray Enchelycore kaniara BOhlke and B6hlke, 19eO was eollected from a shallow coral reef at Amami-oshima Isla]d, Ryukyu Islands, Japan. The species had been known previously flrom only six specimens collected from the Line Islands and Palau, and the present specimen thus represents the first record of the species from Japanese waters. A brief account of the morphology of the Japanese spectmen is provided, as well as a photograph showing its color freshly after col]ection.
A Japanese pipefish, Halicampus punctatus (Kamohara), was redecribed and illustrated based on the holotype and 16 nontype specimens. All specimens were characterized by nine caudal fin rays, differing from the count previously recorded (i.e., 10 rays including the original description). The generic assignment to Halicampus became questionable, the genus being diagnosed by 10 rays. A new pattern of sexual dimorphism was recognized, the inferior tail ridge being notched at junction of rings in males, smooth in females. Brilliant spots on the trunk were hypothesized as functioning to intraspecific recognition, considering relatively deep capture depths (100-150 m).
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