II.—New Palæoniscidæ from the English Coal-Measures

1888 ◽  
Vol 5 (6) ◽  
pp. 251-254 ◽  
Author(s):  
R. H. Traquair

Of this I have seen only two specimens. One of them, slightly longer than the other, measures 3½ inches in length up to the commencement of the caudal fin, which is deficient in both; the greatest depth of the body ½½ inch, the length of the head nearly the same. The dorsal fin is opposite the interval between the ventral and the anal; both dorsal and anal are triangular acuminate in shape, with delicate rays which at first are somewhat distantly articulated, the joints being ornamented with one or two longitudinal sulci. The pectorals are not seen in either specimen, but the smaller of the two shows a well-preserved ventral, which is pretty large, and acuminate in shape.

Zootaxa ◽  
2019 ◽  
Vol 4691 (5) ◽  
pp. 444-460 ◽  
Author(s):  
WILLIAM T. WHITE ◽  
FAHMI FAHMI ◽  
SIMON WEIGMANN

A new genus and species of catshark is described based on a single specimen collected off Ambon in the Maluku Islands of eastern Indonesia. Akheilos suwartanai belongs to the subfamily Schroederichthyinae which differs from the other catsharks in a combination of: similar sized dorsal fins, supraorbital crests present, pseudosiphon present on claspers, broad subocular ridges under eyes, posterior nasal flaps present, tips of rostral cartilage fused into a rostral node. It represents the first record of this subfamily outside of the Americas. Akheilos differs from the other genus in the subfamily, Schroederichthys in a combination of: clasper groove not fused dorsally, ventral lobe of caudal fin produced, more intestinal valve turns, anal fin slightly larger than second dorsal fin, and in colour pattern. 


Zootaxa ◽  
2004 ◽  
Vol 454 (1) ◽  
pp. 1 ◽  
Author(s):  
ANTON LAMBOJ

Pelvicachromis rubrolabiatus and P. signatus are described from Guinea. They differ from other members of Pelvicachromis, except P. humilis, in having two contiguous tubular infraorbital ossicles instead of three with a gap between the 2 nd and 3 rd and in displaying a color pattern of seven to eight dark vertical bars during certain behavioral situations. Pelvicachromis rubrolabiatus differs from P. humilis and P. signatus in having seven instead of eight vertical bars on the body and from P. signatus in having a lesser preorbital depth. Pelvicachromis signatus differs from P. humilis in the presence of characteristic black markings in the dorsal and caudal fin of males, a black spot on the caudal peduncle of females and occasionally one or two black spots in the female s dorsal fin.


Zootaxa ◽  
2008 ◽  
Vol 1822 (1) ◽  
pp. 1 ◽  
Author(s):  
JONATHAN W. ARMBRUSTER

Peckoltia contains 12 described species, eight of which are considered valid. Peckoltia arenaria, P. filicaudata, and P. ucayalensis are recognized as synonyms of P. bachi and P. kuhlmanni is recognized as a synonym of P. vittata. In addition, two new species are described. The type species of Peckoltichthys and Sophiancistrus are synonyms of P. bachi and both genera are recognized as junior synonyms of Peckoltia. The species of Peckoltia range throughout much of the Amazon basin, the upper Orinoco, the upper Essequibo, and perhaps the Maroni, and can be identified from most other ancistrins by having dentaries that form angle of 90° or less and from others with angled dentaries by lacking the synapomorphies of those genera. The species of Peckoltia vary from one another mostly in coloration. Peckoltia braueri, P. caenosa n. sp., P. cavatica and P. vittata lack spots on the head while the other species have them. Peckoltia braueri and P. cavatica have orange bands in the dorsal and caudal fins and have the bones and plates of the head and nape outlined in black (vs. no orange bands and head plates and bones not outlined in black in P. caenosa and P. vittata). Peckoltia caenosa has a color pattern consisting of dark vermiculations on the head and abdomen (vs. saddles or blotches on the head and faint dark spots on the abdomen in P. vittata). Among the species with spots on the head, P. lineola n. sp. and P. vermiculata have some of the spots combining to form vermiculations (vs. spots free in P. bachi, P. brevis, P. furcata, and P.oligospila) with the vermiculations larger than the pupil in P. lineola and narrower in P. vermiculata and the vermiculations radiating from a central point in P. vermiculata vs. no such pattern in P. lineola. Peckoltia bachi can be identified from the other species by having widened pelvic-fin spines that can be pulled ventrally such that they are completely ventral and parallel to the body (vs. pelvic-fin spines narrow and cannot be adducted ventral to body) and by having the eye low on the head (vs. high). Peckoltia brevis can be identified from P. furcata and P. oligospila by having well-developed dorsal saddles (vs. saddles faint), no spots on the body behind the nape (vs. spots generally present behind the nape); from P. oligospila by having bands in the caudal fin (vs. spots); and from P. furcata by having the lower caudal-fin spine longer than the upper (vs. upper spine longer). Peckoltia furcata can be identified from P. oligospila by having the upper caudal-fin spine longer than the lower (vs. lower spine longer) and by having bands in the caudal fin (vs. spots). Ancistrus yaravi had been recognized as a species of Peckoltia. The type of A. yaravi is lost, but the original description suggests that the species is the senior synonym of Neblinichthys roraima. A revised morphological phylogeny demonstrates the lack of support for Peckoltia and Hemiancistrus as monophyletic, and phenetic definitions are provided for the two genera. The phylogeny also demonstrates a lack of support of the genus Watawata.


Zootaxa ◽  
2021 ◽  
Vol 4938 (5) ◽  
pp. 559-570
Author(s):  
CÜNEYT KAYA ◽  
BARAN YOĞURTÇUOĞLU ◽  
JÖRG FREYHOF

Oxynoemacheilus amanos, new species, is described from İncesu spring in the upper Hupnik drainage, a northern tributary of the lower Orontes in Turkey. It is distinguished from the other Oxynoemacheilus species in the Eastern Mediterranean Sea basin by possession of an incomplete lateral line with 23–45 pores, terminating between the vertical through the dorsal fin origin and the anus, 10–13 pores in the infraorbital canal, a deeply emarginate caudal fin, no suborbital groove in the male, and a series of irregularly shaped and set dark-brown bars on the flank, not connected to saddles on the back.  


1906 ◽  
Vol s2-50 (198) ◽  
pp. 333-376
Author(s):  
EDWIN S. GOODRICH

The chief observations described above may be summarised as follows : The development of the median dorsal fins is essentially similar to that of the paired fins. They arise as longitudinal folds, into which grow buds from the myotomes. Some fourteen or sixteen myotomes contribute to the fin each one muscle-bud. Concentration sets in almost from the first appearance of the buds; it is chiefly, if not entirely, due to the body growing faster than the fin. Along the greater part of the dorsal fin each muscle-bud becomes converted into one radial muscle. At the extreme ends of the fins the exact metameric origin of the muscles is difficult to trace and is somewhat obscured. Only here fusion of neighbouring segmental buds perhaps takes place. At certain stages slender strands of embryonic tissue connect the bases of the radial muscles; these are probably rudiments of the nerve-plexus. Neither the study of development nor of the adult structure affords any definite evidence that the primitive metamerism of the musculature is lost. Experiments seem to establish that the radial muscles remain haploneurous, retaining their primitive connection with the nerve belonging to that myotome from which they have been developed. The nerve- "plexus" of the fins is composed of intertwining sensory fibres, along or through which the motor fibres proceed to their destination without mixing with those of other segments. There is The chief observations described above may be summarised as follows : The development of the median dorsal fins is essentially similar to that of the paired fins. They arise as longitudinal folds, into which grow buds from the myotomes. Some fourteen or sixteen myotomes contribute to the fin each one muscle-bud. Concentration sets in almost from the first appearance of the buds; it is chiefly, if not entirely, due to the body growing faster than the fin. Along the greater part of the dorsal fin each muscle-bud becomes converted into one radial muscle. At the extreme ends of the fins the exact metameric origin of the muscles is difficult to trace and is somewhat obscured. Only here fusion of neighbouring segmental buds perhaps takes place. At certain stages slender strands of embryonic tissue connect the bases of the radial muscles; these are probably rudiments of the nerve-plexus. Neither the study of development nor of the adult structure affords any definite evidence that the primitive metamerism of the musculature is lost. Experiments seem to establish that the radial muscles remain haploneurous, retaining their primitive connection with the nerve belonging to that myotome from which they have been developed. The nerve- "plexus" of the fins is composed of intertwining sensory fibres, along or through which the motor fibres proceed to their destination without mixing with those of other segments. There is probably no real motor plexus, but the motor nerves may be gathered together into more or less longitudinal collectors, and become again sorted out on reaching the musculature. Such collectors are found at the base of the dorsal fins, compounded of some fourteen to sixteen segmental rami pterygiales. All the fins remain throughout development in approximately the same position. Apparent change of place may be brought about by concentration being greater in the one direction than in the other. This is especially the case with the dorsal fins, the anterior edge of which may undergo a relative shifting over some ten segments. The general bearing of these results has been sufficiently discussed in the Introduction (p. 334), and need not again be dealt with here. But it may be pointed out how completely they support the lateral fold theory of the origin of the paired fins.


2001 ◽  
Vol 204 (17) ◽  
pp. 2943-2958 ◽  
Author(s):  
Eliot G. Drucker ◽  
George V. Lauder

SUMMARYA key evolutionary transformation of the locomotor system of ray-finned fishes is the morphological elaboration of the dorsal fin. Within Teleostei, the dorsal fin primitively is a single midline structure supported by soft, flexible fin rays. In its derived condition, the fin is made up of two anatomically distinct portions: an anterior section supported by spines, and a posterior section that is soft-rayed. We have a very limited understanding of the functional significance of this evolutionary variation in dorsal fin design. To initiate empirical hydrodynamic study of dorsal fin function in teleost fishes, we analyzed the wake created by the soft dorsal fin of bluegill sunfish (Lepomis macrochirus) during both steady swimming and unsteady turning maneuvers. Digital particle image velocimetry was used to visualize wake structures and to calculate in vivo locomotor forces. Study of the vortices generated simultaneously by the soft dorsal and caudal fins during locomotion allowed experimental characterization of median-fin wake interactions.During high-speed swimming (i.e. above the gait transition from pectoral- to median-fin locomotion), the soft dorsal fin undergoes regular oscillatory motion which, in comparison with analogous movement by the tail, is phase-advanced (by 30% of the cycle period) and of lower sweep amplitude (by 1.0cm). Undulations of the soft dorsal fin during steady swimming at 1.1bodylengths−1 generate a reverse von Kármán vortex street wake that contributes 12% of total thrust. During low-speed turns, the soft dorsal fin produces discrete pairs of counterrotating vortices with a central region of high-velocity jet flow. This vortex wake, generated in the latter stage of the turn and posterior to the center of mass of the body, counteracts torque generated earlier in the turn by the anteriorly positioned pectoral fins and thereby corrects the heading of the fish as it begins to translate forward away from the turning stimulus. One-third of the laterally directed fluid force measured during turning is developed by the soft dorsal fin. For steady swimming, we present empirical evidence that vortex structures generated by the soft dorsal fin upstream can constructively interact with those produced by the caudal fin downstream. Reinforcement of circulation around the tail through interception of the dorsal fin’s vortices is proposed as a mechanism for augmenting wake energy and enhancing thrust.Swimming in fishes involves the partitioning of locomotor force among several independent fin systems. Coordinated use of the pectoral fins, caudal fin and soft dorsal fin to increase wake momentum, as documented for L. macrochirus, highlights the ability of teleost fishes to employ multiple propulsors simultaneously for controlling complex swimming behaviors.


1878 ◽  
Vol 9 ◽  
pp. 427-444
Author(s):  
R. H. Traquair

Elonichthys ovatus, sp. nov. Traquair.Of this I have only seen one specimen, from the limestone of Burdiehouse, and preserved in the Edinburgh Museum of Science and Art.Description.—Allowing for the anterior part of the head, which is deficient, the entire length of the specimen to the extreme point of the upper lobe of the caudal fin would be about 5⅝ inches; the greatest depth of the body in front of the dorsal fin is 1½ inch. The distance from the origin of the pectoral fin to that of the ventral is a little over 1 inch, to opposite the commencement of the dorsal 1¼ inch, to opposite that of the anal 1½ inch, and to opposite that of the lower lobe of the caudal nearly 3 inches. The general form of the fish is thus remarkably short, deep, and ovoid, and its general appearance does not indicate that its peculiar form is due to post mortem distortion or change.


Zootaxa ◽  
2017 ◽  
Vol 4311 (1) ◽  
pp. 96 ◽  
Author(s):  
HIRANYA SUDASINGHE

Schistura madhavai, new species, is described from Suriyakanda, Sri Lanka. It is distinguished from all other species of Schistura in the peninsula of India and Sri Lanka by the combination of the following characters: 8–9 wide, brown postdorsal bars separated by narrow, white interspaces; width of interspaces ¼–⅓ times width of bars; black bar at caudal-fin base wider than interspaces on the body; incomplete lateral line, ending beneath dorsal-fin base; absence of an axillary pelvic lobe; adpressed pelvic fin just reaching anus; origin of the pelvic fin on a vertical through the last unbranched dorsal-fin ray. Schistura notostigma, the only other Sri Lankan species of Schistura, is redescribed. It can be distinguished from all other species of Schistura in the peninsula of India and Sri Lanka by the combination of the following characters: 6–7 wide, brown postdorsal bars; width of interspaces ½–1 times width of bars; complete, black bar at caudal-fin base narrower than width of interspaces between bars on body; emarginate caudal fin; incomplete lateral line ending beneath dorsal-fin base; adpressed pelvic fin surpassing anus; and origin of pelvic fin beneath first branched dorsal-fin ray. Schistura madhavai is separated from S. notostigma by an uncorrected pairwise distance of 3.0–3.8% for the 16S rRNA gene fragment. 


1992 ◽  
Vol 70 (2) ◽  
pp. 264-267 ◽  
Author(s):  
Arne Johan Jensen ◽  
Bjørn Ove Johnsen

Site specificity of Gyrodactylus salaris on 853 Atlantic salmon (Salmo salar) parr infected with 1 – 10 625 parasites was studied in the River Lakselva in northern Norway. At low intensities (< 100), the dorsal fin was the principal site of attachment, followed by the pectoral and anal fins. However, the distribution of parasites on the fish, and their crowding, varied with infection intensity. When the intensity increased to more than 100, more parasites were located on the caudal fin, and when it exceeded 1000, the body of the fish was also heavily infected.


2015 ◽  
Vol 17 (3) ◽  
pp. 224
Author(s):  
Wila Rumina Nento ◽  
Tati - Nurhayati ◽  
Ruddy - Suwandi

Tuna is one of the mainstay fisheries commodities that involve many of the ordinary fishermen. The handling usually still not follows the principles of good handling that causing the poor quality as the result.The aims of this research were to analyze and to determine the quality of tuna meat (the abdominal wall, dorsal fin, and caudal fin). Raw material yellowfin tuna meat prepared for the light, the meat section of the abdominal wall, dorsal fin, and caudal fin. The result of organoleptic analysis showed that the tuna meat was above the minimum value for the criteria of fresh fish. The result of TVB analysis showed that the meat on the caudal fin had the highest value and significantly different with the other, but still exist on the safe limits and on the fresh category. For the result of analysis in histamine, it shown that at the fourth hour the meat at the dorsal fin had the histamine content which were above the minimum that have been recommended. For the result of analysis in peroxide number, it shown that the tuna meat did not sustain the fat damage until the fourth hour after the catching process. And for the result of analysis in TPC, it showed that at the fourth hour the tuna meat on the pectoral fin had the highest number of total colony and significantly different with the other.<br />Keywords: handling, histamine, light flesh, microbiology, yellowfin


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