Description of transformation larvae and a juvenile of the dextral flounder,poecilopsetta praelonga (pleuronectidae, poecilopsettinae) from the northwestern waters of australia

Three late metamorphic transformation larvae ofPoecilopsetta praelonga (68.0–82.3 mm SL) and a juvenile (92.7 mm SL) captured from the waters off northwestern Australia (400–460 m deep) are described. The transformation larvae ofP. praelonga are distinguishable from the congeners of the same stage in having relatively low body depth (2.20–2.44 in SL), relatively large maxilla extending to anterior one-third of lower eye, and seven and six distinct spots along the dorsal and ventral margins of ocular side body, respectively. In the smallest specimen, the intestine was expanded posteriorly beyond the posterior wall of visceral cavity, but not in the larger specimens. The pectoral fin rays and the spines of scales were supposed to begin to be formed by about 80 mm SL. Ontogenetic changes which include decreasing ratios of upper jaw length to head length. and increasing ratios of depth of body muscle to body depth, were observed, based on a comparison of transformation larvae, a juvenile and adults.     

Juvenile development of a flathead,Suggrundus meerdervoortii (Scorpaeniformes: Platycephalidae)

Juvenile development ofSuggrundus meerdervoortii was described, based on twelve specimens (12.9–43.8 mm SL) collected from off Yamagata Prefecture, Japan Sea. Two exterior openings in the lateral line scales were completed at ca. 35 mm SL, with the interopercular flap and iris lappet being visible at ca. 44 mm SL, these all being useful taxonomic characters. In juveniles and additional young and adult specimens (ca. 70–191 mm SL), the proportions of head length, snout length, orbital diameter, caudal peduncle depth and caudal fin length decreased with growth; interorbital width decreased rapidly until ca. 70 mm SL, but more or less stabilised thereafter (70–191 mm SL).     

A new deepwater assfish, <Emphasis Type="Italic">Bassozetus nielseni</Emphasis> sp. nov. (Ophidiiformes: Ophidiidae), from the North Atlantic and West Indian oceans

A new deepwater assfish, Bassozetus nielseni sp. nov., is described from 29 specimens [147–615 mm in standard length (SL)] collected from the North Atlantic and West Indian oceans. It is distinguished from 13 congeners by the following combination of characters: dorsal-fin rays 122–129, long rakers on first gill arch 11–14, oblique scales 20–25, abdominal vertebrae 13–14, head length 18.1–21.3 % SL, body depth at anal-fin origin 8.2–14.6 % SL, predorsal length 16.4–20.1 % SL, tail length 62.7–68.0 % SL, posterior tip of pelvic-fin rays anterior to anus, a single median basibranchial tooth patch, dorsal margin of sagittal otolith smooth, and fins pale yellowish brown (preserved condition).     

The red-fin Decapterus group (Perciformes: Carangidae) with the description of a new species, Decapterus smithvanizi

The carangid genus Decapterus can be defined by having a single finlet behind both the second dorsal and anal fins, and lacking scutes on the anterior curved part of the lateral line. We revised taxonomically the species of Decapterus with red-colored caudal fins (the red-fin Decapterus group) and established that the group consisted of the following four species: Decapterus akaadsi Abe 1958, distributed in the eastern Indian Ocean and West Pacific from the Andaman Sea to Indonesia, north to central Japan; Decapterus kurroides Bleeker 1855, distributed in the Indo-West Pacific from the Red Sea and eastern coast of Africa to eastern Australia, north to the Philippines; Decapterus smithvanizi sp. nov., occurring in the Andaman Sea, the South China Sea, and Indonesia; and Decapterus tabl Berry 1968, distributed circumglobally in tropical and subtropical seas. The diagnostic characters of these species are as follows: D. akaadsi—curved part of lateral line with 43–53 cycloid scales, straight part of lateral line with 26–29 scutes, head length 26.7–30.1 % SL, and body depth 24.0–27.9 % SL; D. kurroides—curved part of lateral line with 45–51 cycloid scales, straight part of lateral line with 30–32 scutes, head length 30.3–33.0 % SL, and body depth 23.4–26.4 % SL; D. smithvanizi—lower gill rakers 25–31, curved part of lateral line with 54–62 cycloid scales, body depth 19.4–22.5 % SL, pectoral-fin tip usually beyond the level of second dorsal-fin origin; D. tabl—tip of upper jaw usually hooked and opercular membrane partly serrated in larger specimens, lower gill rakers 28–33, curved part of lateral line with 61–72 cycloid scales, body depth 16.6–23.0 % SL, pectoral-fin tip not reaching to the level of second dorsal-fin origin.     

Three new species of the genus <Emphasis Type="Italic">Acropoma</Emphasis> (Perciformes: Acropomatidae) from the Indian Ocean

Three new species of Acropoma are described from the Indian Ocean. These species have been identified as “A. japonicum Günther 1859” by many authors, but clearly differ from A. japonicum in the shape and length of the luminous gland, counts of pectoral-fin rays and scales between first dorsal-fin base and lateral line, and other diagnostic characters. Acropoma heemstrai sp. nov. is described on the basis of 17 specimens (53.1–121.0 mm standard length: SL) collected from South Africa and Mozambique. It is distinguished from other congeners by its unique moderate Y-shaped luminous gland, extending from the throat to midway between the origins of the pelvic and anal fins, (luminous gland length 23.1–27.0% SL) and a pointed protrusion on the symphysis of lower jaw. Acropoma lacrima sp. nov. is described on the basis of 6 specimens (64.1–77.9 mm SL) collected from the Arabian Sea. Also, this species has been previously reported as “A. argentistigma Okamoto and Ida 2002” from the Bay of Bengal. It is characterized by having a vertical line on the cheek, short U-shaped luminous gland (luminous gland length 15.0–16.0% SL), and weakly ctenoid and cycloid scales on the side of the body. Acropoma neglectum sp. nov. is described on the basis of 5 specimens (105.3–168.5 mm standard length: SL) collected from the Gulf of Aqaba, northern Red Sea. It is similar to A. japonicum in having a short U-shaped luminous gland, but differs in having a shorter luminous gland (12.0–13.4% SL vs. 17.0–20.8% SL in A. japonicum), 3 scales between first dorsal-fin base and lateral line (vs. 4 scales in A. japonicum), and 16–17 pectoral-fin rays [vs. 14–16 (modally 15) in A. japonicum].     

<Emphasis Type="Italic">Abudefduf nigrimargo</Emphasis>, a new species of damselfish (Perciformes: Pomacentridae) from Taiwan

A new species of damselfish, Abudefduf nigrimargo (Pomacentridae), is described on the basis of six specimens (91.8–119.5 mm standard length; SL) from Taiwan. Although similar to A. caudobimaculatus Okada and Ikeda 1939, A. saxatilis (Linnaeus 1758), A. troschelii (Gill 1862) and A. vaigiensis (Quoy and Gaimard 1825) in having five dark bands on the lateral surface of the body with yellowish interspaces dorsally, the new species can be distinguished from the others by the following combination of characters: 18–19 (mode 19) pectoral-fin rays; 20–23 (22) tubed lateral-line scales; 7–8 (7)?+?14–16 (16)?=?21–24 (23) gill rakers; relatively greater body depth and longer pectoral-fin length [57.3–60.8% (mean 59.0%) of SL and 36.8–40.8% (38.5%) of SL, respectively]; 5 scale rows on cheek; scales on suborbit, usually continuous over basal area of lacrimal; many scales on anteroventral region of head; scale covering on preopercle and interopercle continuous; scales on dorsal and lateral body surfaces with blackish margin (indistinct in subadult), second and third black bands on body not extending dorsally onto membranes of spinous dorsal fin; anterior and upper margins of fourth black band usually level with sixth dorsal-fin soft ray base and not extending onto small scales on the dorsal-fin base, respectively; and caudal-fin base without black spots.     

A new genus and species of cyprinid fish (Actinopterygii,Cyprinidae) from the Arabian Peninsula,and its phylogenetic and zoogeographic affinities

Arabibarbus hadhrami, a new species of cyprinid fish from the Hadhramaut Province of Yemen, is described. It has modally 30 scales (29–32) in the lateral line, the wedge-shaped head is longer (27.8–32.5 % SL) and higher (15.5–18.4 % SL) than in its congeners. The body is slender and laterally flattened. The dorsal fin is high (26.5–32.4 % SL) and well ossified. The pectoral fins (19.9–23.9 % SL) and pelvic fins (16.8–19.8 % SL) are longer than in its congeners. Two closely related species, Arabibarbus arabicus and Arabibarbus grypus are re-described and compared to the new species. Based on morphological and molecular characters the new genus Arabibarbus is erected for these three species. It is characterised by medium to large body size, an ossified, smooth principal dorsal fin ray, eight branched dorsal and five branched anal fin rays, large shield-shaped scales with numerous parallel radii, a lateral line with 29 to 44 scales, pharyngeal teeth that are hooked at their tips, their count being 2.3.5–5.3.2 and the possession of two pairs of barbels. Arabibarbus hadhrami is the type species of the new genus. The phylogenetic position of the new genus is analysed, based on the mitochondrial cytochrome b gene. It is the sister taxon to the genus Carasobarbus Karaman, 1971 and closely related to Mesopotamichthys Karaman, 1971, Pterocapoeta Günther, 1902 and ‘Barbus’ reinii Günther, 1874. Arabibarbus probably colonised the Arabian Peninsula about 4 Ma ago, coming from the Tigris-Euphrates drainage in the East via Wādī ar Rimah/Wādī al Bā?in.     

Review of the clingfish genus <Emphasis Type="Italic">Kopua</Emphasis> (Gobiesocidae: Trachelochisminae) in Japan,with description of a new species

A taxonomic review of the clingfish genus Kopua (Gobiesocidae: Trachelochisminae) in Japan recognizes three species: K. japonica Moore, Hutchins and Okamoto 2012, K. vermiculata Shinohara and Katayama 2015 and K. yoko sp. nov. Kopua japonica and K. vermiculata are redescribed with revised diagnoses on the basis of 20 specimens (10.4–30.4 mm standard length; SL) and the holotype, respectively. Kopua japonica is similar to K. vermiculata in head sensory pore characters (normally single nasal and postocular canal pores). However, the former differs distinctly from the latter as follows: 6–8 (modally 7) gill rakers (vs. 4 or 6); 31–33 (33) vertebrae (vs. 35); anus slightly closer to posterior margin of disc than to anal-fin origin (vs. much closer to posterior margin of disc); snout length 5.3–8.7 (mean 7.0) % SL (vs. 9.2 % SL); disc length 21.2–24.0 (22.8) % SL (vs. 18.8 % SL); pre-dorsal- and anal-fin lengths 72.9–78.4 (75.2) and 78.1–82.8 (80.1) % SL, respectively (vs. 67.5 and 73.6 % SL); and two stripes on cheek (vs. a triangular blotch). Kopua yoko sp. nov., based on 14 specimens (17.7–28.8 mm SL) from the Pacific coast of southern Japan, Sea of Japan and the East China Sea, is characterized by the following combination of characters: 6 or 7 (modally 6) dorsal-fin rays; 4–6 (5) anal-fin rays; 21 or 22 (21) pectoral-fin rays; 4–6 (5 or 6) gill rakers; 31–33 (31) vertebrae; a single (rarely two) nasal canal pores; two lacrimal and preopercular canal pores; snout length 6.5–7.9 (mean 7.1) % SL; gill opening depth 5.8–7.1 (6.5) % SL; least interorbital width 2.0–3.7 (2.6) % SL; disc length 20.3–25.0 (23.1) % SL, disc region D without flattened papillae; caudal-peduncle depth 8.1–10.2 (9.2) % SL; anus slightly closer to posterior margin of disc than to anal-fin origin; pre-dorsal- and anal-fin lengths 71.6–77.1 (73.9) and 77.0–83.7 (80.4) % SL, respectively; post-dorsal-caudal length 12.6–15.0 (13.8) % SL; arch-shaped blotches on lateral aspect of body; and two reddish-orange stripes on cheek. Morphological changes with growth in K. japonica and K. yoko sp. nov. are also described.     

Salmo kottelati,a new species of trout from Alak?r Stream,draining to the Mediterranean in southern Anatolia,Turkey (Teleostei,Salmonidae)

Salmo kottelati sp. n., is described from Alakır Stream (Mediterranean basin) in Turkey. It is distinguished from other Anatolian Salmo species by a combination of the following characters (none unique to the species): general body colour greenish to silvery in life; 7–9 parr marks along lateral line; four dark bands on flank absent in both sexes; black ocellated spots few, present only on upper part of flank in individuals smaller than 160 mm SL but in larger both males and females black spots numerous and located on back and middle and upper part of flank; red spots few to numerous, scattered on median, and half of lower and upper part of flank; head long (length 29–33% SL in males, 26–32 in females); mouth large (length of mouth gape 13–19% SL in males, 12–15 in females); maxilla long (length 10–13% SL in males, 8–12 in females); 105–113 lateral line scales; 24–29 scale rows between lateral line and dorsal-fin origin, 17–19 scale rows between lateral line and anal-fin origin; 13–15 scales between lateral line and adipose-fin insertion.     

Larval morphology and occurrence of the louvar,Luvarus imperialis (Luvaridae)

A total of nineteenLuvarus imperialis larvae, 3.5 to 10.7 mm in standard length were collected during the cruises of R/V Shoyo Maru in the northwestern Pacific and eastern Indian Ocean. This paper describes meristic and morphological features of these specimens throughout development. The features particularly noted in postlarvae and early juveniles ofL. imperialis are: 1) large head with a wide snout, 2) oval and well-compressed body, 3) large pectoral fins, 4) developed and finely serrated dorsal and pelvic spines, 5) well-developed head spination, 6) minute spines on the soft rays of all fins in larvae larger than about 5.6 mm SL, and 7) very rough body surface associated with the development of spiny-edged scales. Larvae ofL. imperialis occur mostly in the coastal waters between lat. 40°N and 40°S of the world oceans, suggested the spawning in temperate waters.     

The growth ofOreochromis andersonii (Pisces: Cichlidae) from the Okavango Delta,Botswana, and a comparison of the scale and otolith methods of ageing

Synopsis Otoliths and scales were used for age and growth determination ofOreochromis andersonii from the Okavango Delta, Botswana. Marginal increment analysis showed that an annulus was formed in both the scales and otoliths during the dry summer period. Using scales, the growth ofO. andersonii was described by L_t = 285.27(1-e^{-0.26(t+2.02)}) mm SL and using otoliths by the equation L_t = 267.48(1-e^{-0.25(t+2.18)}) mm SL. Maximum age estimates of 10 years using scales and 13 years using otoliths were obtained and the growth curves were significantly different (p < 0.01). Age estimation using scales tended to over-emphasise growth inO. andersonii resulting in larger predicted lengths-at-age. For this reason, otoliths are considered to be more reliable and suitable than scales in determining the age and growth of this species.     

Osteological development in the Japanese sardine,Sardinops melanostictus

The development of all osteological elements, except scales, of the Japanese sardine,Sardinops melanostictus, is described from newly-hatched larvae to adult fishes. Newly-hatched larvae lacked osteological elements. Part of the head skeleton began to develop in 53 hour old larvae (4.2 mm in notochord length [NL]). Larvae at the first-feeding stage (77 hours, 5.5 mm NL) possessed several elements of the head skeleton and pectoral fin supports. In a 10.5 mm NL specimen, part of the caudal and dorsal fin supports were apparent. The centra appeared in specimens 18–22.7 mm in standard length (SL). Gill rakers were first observed in the lower branchial arches at 13 mm NL and spine-like processes with spiny nodules from about 25 mm SL. The distance between the predorsal and first dorsal proximal radial relative to SL rapidly decreased with forward translocation of the dorsal fin and became constant beyond approximately 34 mm SL. At this stage, most basic osteological elements were established. Completion of the osteological structure was characterized by the disappearance of the dentary teeth at 60–70 mm SL. Based on the osteological development, ontogenetic intervals consisting of four periods and eight phases were recognized.     

Redescriptions ofGerres baconensis (Evermann & Seale, 1907),G. equulus Temminck & Schlegel, 1844 andG. oyena (Forsskål, 1775), included in the “G. oyena complex”, with notes on other related species (Perciformes: Gerreidae)

The gerreid species,Gerres baconensis (Evermann &; Seale),G. equulus Temminck &; Schlegel andG. oyena (Forsskål), were re-assessed as valid following examination of their holotypes and other specimens, and included in the “G. oyena complex”.Gerres haconensis is currently known only from Bacon, Luzon Island, Philippines and the Ogasawara (=Bonin) Islands, Japan, andG. equulus only from southern Japan (except Ryukyu Islands) and southern Korea.Gerres oyena is widely distributed in the Indo-West Pacific (in Japan, only from the Ryukyu Islands).Gerres baconensis differs from bothG. equulus andG. oyena in having higher counts of both the pored lateral line scales (39–42 vs 35–41 in the latter two species) and the lower gill raker series (8 or 9 vs. usually 7). A U-shaped premaxillary groove, formed on the dorsum of the forehead by the long ascending processes of the premaxillae, is scaleless inG. equulus andG. oyena, whereas it is fully scaled just behind the level of the posterior nostrils inG. baconensis over ca. 160 mm in standard length (SL) (partially scaled in specimens of ca. 100 mm SL).Gerres equulus differs fromG. oyena in having the posterior margin of the maxilla not extending beyond a vertical through the anterior margin of the inner dermal eye opening, shorter second dorsal and anal fin spines (means 18.5% and 8.5% of SL, respectively vs. 21.2% and 10.3% of SL), lower body depth at first anal fin spine base (27.0% vs. 29.6% of SL) and dorsomedial U-shaped groove scaleles throughout life (vs. tiny squamation anteriorly in specimens over ca. 130 mm SL). OtherGerres species of uncertain status and/or related species are discussed.     

<Emphasis Type="Italic">Amblyceps improcerum</Emphasis>, a new sisoroid catfish from Kachin State,Myanmar (Teleostei: Siluriformes: Amblycipitidae)

A new species of amblycipitid catfish is here described from the Indawgyi Lake basin of the Irrawaddy River drainage in Kachin State, Myanmar as Amblyceps improcerum, new species. It can be distinguished from congeners in having a unique combination of the following characters: lower jaw longer than upper; head length 17.4–22.3% SL; head width 13.7–15.2% SL; head depth 9.0–11.7% SL; interorbital distance 31–39% HL; eye diameter 7–10% HL; 37–38 vertebrae; lateral line incomplete; predorsal length 25.5–30.7% SL; smooth posterior margin of pectoral spine; pectoral-fin length 13.5–16.8% SL; pelvic-fin length 9.6–13.4% SL; dorsal-to-adipose distance 25.2–28.7% SL; length of adipose-fin base 19.4–23.3% SL; adipose fin separate from dorsal procurrent caudal-fin rays; preanal length 62.1–66.9% SL; body depth at anus 9.8–12.8% SL; depth of caudal peduncle 10.1–12.6% SL; length of caudal peduncle 21.4–24.0% SL, post-adipose distance 15.8–17.8% SL; weakly-forked caudal fin with short broadly, rounded lobes (length of longest ray 1.3–1.5 times length of median rays); centrally projecting hooks on proximal lepidotrichia of median caudal-fin rays absent.     

Age and growth in a newly-established invasive population of topmouth gudgeon

Specimens of invasive topmouth gudgeon, Pseudorasbora parva, from Šúr Pond (Bratislava, Slovakia) were examined to assess age and growth, and to determine whether this recently-established invasive population employs a less specialized ontogenetic trajectory than the specialized form typical of native and/or long-time established populations. Samples were collected in October 2004 (n=143). Standard length (SL) ranged from 18.16 mm to 67.57 mm (mean 32.56 mm), and eviscerated body weight ranged from 0.10 to 5.02 g (mean 0.63 g). Scale caudal diameter ranged from 0.52 to 2.42 mm (mean 1.08 mm). SL at which the scales started to form was estimated to be 1.58 mm. The population was represented with 5 age groups, from 0+ to 4+. Relative to other populations for which comparable data are available the recently-established population of topmouth gudgeon was found to mature at smaller size and at a younger age compared to native and/or long-time established populations (all specimens bigger than 25.0 mm SL, and 94% of specimens from the age group I were already mature).     

Redescription of a rare deepwater cardinalfish, Epigonus ctenolepis Mochizuki and Shirakihara 1983, and comparison with related species (Perciformes: Epigonidae)

A rare epigonid fish, Epigonus ctenolepis Mochizuki and Shirakihara 1983, is redescribed in detail on the basis of two type specimens (90.0??8.0?mm standard length, SL) and an additional specimen (128.8?mm SL) collected from Suruga Bay, Japan, and compared with related species of Epigonus. The species is characterized by the following combination of characters: first dorsal-fin rays VII, second dorsal-fin rays I, 9??0, vertebrae 10?+?15, pored lateral-line scales 52??3 (hypural end 48??9?+?caudal fin 4), pyloric caeca 9??1, total gill rakers 24??5, presence of a pungent opercular spine, lateral-line scales ctenoid, absence of a maxillary mustache-like process, and absence of a rib on the last abdominal vertebra. A key to the Epigonus species characterized by a pungent opercular spine is provided.     

Prey use of wetland benthivorous sunfishes: ontogenetic, interspecific and seasonal variation

The intensity of competitive interactions between fishes is partly determined by prey use and ontogenetic niche shifts. In a wetland where distinct habitat shifts are missing we compared prey use of three generalist benthivorous sunfishes to look for evidence of ontogenetic, interspecific, and “seasonal” variation in prey composition. Diet analysis revealed evidence of diet ontogeny in warmouth (Lepomis gulosus, 30–152 mm standard length, SL), but not in bluespotted sunfish (Enneacanthus gloriosus, 30–47 mm SL) or dollar sunfish (Lepomis marginatus, 30–60 mm SL). Bluespotted and dollar sunfishes consumed small dipteran and amphipod prey and had similar diets in both seasons suggesting a potential for strong interspecific competition. In the dry season, warmouth shifted from using smaller insect prey to larger decapod and fish prey with increasing size. This shift to prey types that were little used by the other species reduced dietary niche overlap with the other sunfishes. After drought and re-flooding (in the wet season), decapods and small fish were less abundant in the wetland and the warmouth ontogenetic shift was less distinct. When matched for gape width, prey composition differed between warmouth and both dollar and bluespotted sunfishes in the wet season, suggesting differences in sunfish foraging modes, but prey use differences were less clear in the dry season when prey were abundant. Both warmouth ontogenetic diet shifts and seasonal variation in prey use (probably mediated by prey abundance) had strong influences on diet overlap and therefore the potential for intra- and interspecific competition between sunfishes in this wetland ecosystem.     

Osteological development of the lophiid anglerfish,lophius gastrophysus

The osteological development of the head skeleton and dorsal, pectoral, and anal fin supports, are described from cleared and stained specimens ofLophius gastrophysus larvae, ranging from 4.6 to 21.8 mm NL; the results are compared with those of juvenile (79.8 mm SL) and adult (398 mm SL) specimens. Tiny conical teeth are present on the premaxillary, dentary, palatine and vomer since early stage. The first three dorsal fin spines are initially positioned on the midline of body posterior to the supraoccipital, but they migrate forward with growth and become cephalic in juveniles. The forward movement of the dorsal spines is produced by the forward extension of the cartilaginous basal inside the subepidermal space. During the planktonic larval stage the pectoral fins are on the sides of body as in ordinary fishes, but they move ventrad and become leg-like in bottom living juveniles and adults. Ossification of the caudal complex ofL. gastrophysus larvae proceeds very slowly and only the 21.8 mm NL larva has an almost completely ossified caudal complex. Eight principal caudal rays are loosely attached on the posterior edge of the hypurals and no procurrent rays are present. Larvae have well developed parhypurapophysis at the mid-portion of the urostyle which transforms into keel-like structure in juveniles and adults.