Brain and sensory organ morphology in Antarctic eelpouts (perciformes: Zoarcidae: Lycodinae)

Lannoo, Michael J.; Eastman, Joseph T.

doi:10.1002/jmor.10391

Cited by 5 publications

(5 citation statements)

References 46 publications

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“…A notable feature of the development process in R. canadum is that, as the larva adds myomeres to the trunk, new neuromasts supplement the populations of each flank. The neuromast series of the trunk comprises an alignment of single neuromasts, as opposed to the paired neuromasts seen for the anterior lateral line of blue tilapia Oreochromis aureus (Steindachner 1864) (Webb, 1989) or the superficial neuromasts described for the Antarctic species Ophthalmolycus amberensis (Tomo, Marschoff & Torno 1977) (Lannoo & Eastman, 2006). Regarding the cranial canals, the anatomy ( i.e.…”

Section: Discussionmentioning

confidence: 99%

Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation

Salze

Craig²,

Smith

et al. 2011

Journal of Fish Biology

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The morphological development of larval cobia Rachycentron canadum from 3 days post hatch (dph) until weaning (27 dph) was examined using S.E.M. Two groups of fish were studied: a control group (CF), reared under standard feeding protocol, and a group in which prey items were enriched with supplemental taurine (4 g l(-1) day(-1) ; TF). TF fish grew faster (P < 0·001), attained greater size (mean ±s.e. 55·1 ± 1·5 v. 33·9 ± 1·0 mm total length) and had better survival (mean ±s.e. 29·3 ± 0·4 v. 7·1 ± 1·2 %) than CF fish. Canonical variance analysis confirmed findings with respect to differences in growth between the treatment groups with separation being explained by two cranial measurements. S.E.M. revealed that 3 dph larvae of R. canadum (in both groups) possess preopercular spines, superficial neuromasts on the head and body, taste buds in the mouth, an olfactory epithelium which takes the form of simple concave depressions, and primordial gill arches. Gill filaments start to form as early as 6 dph and lamellae buds are visible at 8 dph in both groups. In CF fish, the cephalic lateral line system continues its development at 12-14 dph with invagination of both supra- and infraorbital canals. At the same time, a thorn-like or acanthoid crest forms above the eye. At 14 dph, invaginations of the mandibular and preopercular canals are visible and around 22 dph enclosure of all cranial canals nears completion. In CF larvae, however, completely enclosed cranial canals were not observed within the course of the trial, i.e. 27 dph. In TF larvae, grooves of the cephalic lateral line system form 4 days earlier than observed in CF larvae of R. canadum (i.e. at 8 dph), with enclosure commencing at 16 dph, and completed by 27 dph. Along the flanks of 6 dph larvae of either treatment, four to five equally spaced neuromasts delineate the future position of the trunk lateral line. As myomeres are added to the growing larvae, new neuromasts appear such that at 16 dph a neuromast is associated with each myomere. By 27 dph, the trunk lateral line starts to invaginate in CF larvae, while it initiates closure in TF larvae. These findings elucidate important features of the larval development of R. canadum and show that dietary taurine supplementation benefits larval development, growth and survival in this species. Moreover, they suggest a conditional requirement for taurine in larval R. canadum.

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Section: Discussionmentioning

confidence: 99%

Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation

Salze

Craig²,

Smith

et al. 2011

Journal of Fish Biology

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“…At the time of our original descriptions Lannoo and Eastman, 1995), subependymal expansions were only known from notothenioids. We have since found them in the non-notothenioid Liparidae (Scorpaeniformes; Eastman and Lannoo, 1998), in the Muraenolepididae (Gadiformes; Eastman and Lannoo, 2001), and in the Zoarcidae (Perciformes; Lannoo and Eastman, 2006). Subependymal expansions have also been found in the telencephalon of the Mediterranean sea bass (Cerdá -Reverter et al, 2001a).…”

Section: Brain and Sense Organ Morphology In Non-antarctic Eleginops mentioning

confidence: 95%

Brain and sense organ anatomy and histology of the Falkland Islands mullet, Eleginops maclovinus (Eleginopidae), the sister group of the Antarctic notothenioid fishes (Perciformes: Notothenioidei)

Eastman

Lannoo

2007

Journal of Morphology

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The perciform notothenioid fish Eleginops maclovinus, representing the monotypic family Eleginopidae, has a non-Antarctic distribution in the Falkland Islands and southern South America. It is the sister group of the five families and 103 species of Antarctic notothenioids that dominate the cold shelf waters of Antarctica. Eleginops is the ideal subject for documenting the ancestral morphology of nervous and sensory systems that have not had historical exposure to the unusual Antarctic thermal and light regimes, and for comparing these systems with those of the phyletically derived Antarctic species. We present a detailed description of the brain and cranial nerves of Eleginops and ask how does the neural and sensory morphology of this non-Antarctic notothenioid differ from that seen in the phyletically derived Antarctic notothenioids? The brain of Eleginops is similar to those of visually oriented temperate and tropical perciforms. The tectum is smaller but it has well-developed olfactory and mechanoreceptive lateral line areas and a large, caudally projecting corpus cerebellum. Eye diameter is about twofold smaller in Eleginops than in many Antarctic species. Eleginops has a duplex (rod and cone) retina with single and occasional twin cones conspicuous centrally. Ocular vascular structures include a large choroid rete mirabile and a small lentiform body; a falciform process and hyaloid arteries are absent. The olfactory rosette is oval with 50-55 lamellae, a large number for notothenioids. The inconspicuous bony canals of the cephalic lateral line system are simple with membranous secondary branches that lack neuromasts. In Antarctic species, the corpus cerebellum is the most variable brain region, ranging in size from large and caudally projecting to small and round. "Stalked" brains showing reduction in the size of the telencephalon, tectum, and corpus cerebellum are present in the deep-living artedidraconid Dolloidraco longedorsalis and in most of the deep-living members of the Bathydraconini. Eye diameter is generally larger in Antarctic species but there is a phylogenetic loss of cellularity in the retina, including cone photoreceptors. Some deep-living Antarctic species have lost most of their cones. Mechanosensation is expanded in some species, most notably the nototheniid Pleuragramma antarcticum, the artedidraconid genera Dolloidraco and Pogonophryne, and the deep living members of the bathydraconid tribe Bathydraconini. Reduction in retinal cellularity, expansion of mechanoreception, and stalking are the most noteworthy departures from the morphology seen in Eleginops. These features reflect a modest depth or deep-sea effect, and they are not uniquely "Antarctic" attributes. Thus, at the level of organ system morphology, perciform brain and sensory systems are suitable for conditions on the Antarctic shelf, with only minor alterations in structure in directions exhibited by other fish groups inhabiting deep water. Notothenioids retain a relative balance among their array of senses that reflects their ...

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“…Fanta et al (2001a) studied the feeding behavior of small adults of O. amberensis (*150 mm SL) held in aquaria, where they were active \2 % of the time and their activity was enhanced in darkness. Brain and sensory organ histology of O. amberensis suggested they relied on chemosensation rather than vision to locate food (Fanta et al 2001b;Lannoo and Eastman 2006). In actively searching for food, they touched their mouths to the substrate.…”

Section: Zoarcidsmentioning

confidence: 98%

Feeding biomechanics of five demersal Antarctic fishes

2014

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There is scant information available on the ecomorphology of Antarctic fishes, and especially on their feeding capabilities. We measured interspecific variation in mechanical advantage (MA), force-producing capability, and suction index for the jaws of the five dominant taxa of high-Antarctic fishes: the nototheniid Trematomus bernacchii; the zoarcids Pachycara brachycephalum, Lycodichthys dearborni, and Ophthalmolycus amberensis; and the liparid Paraliparis devriesi. Analysis of variance indicated significant differences in jaw metrics, and ordinations of morphological traits identified three loosely defined groups reflecting their family-level taxonomy. Principal component analyses showed distinct segregation between the nototheniid and the liparid, indicating that they are at the extremes of the feeding performance continuum. The zoarcids fell in the middle, suggesting that they utilize a combination of feeding modes to capture prey. The liparid had the lowest MA and bite force, but a large epaxialis implied a ram-suction-feeding mode. The large adductor mandibulae in the zoarcids P. brachycephalum and L. dearborni suggest that they are capable of grasping mobile prey and manipulating sedentary, hard-shelled macroinvertebrates. The zoarcids had a smaller epaxialis than the liparid and may not be as efficient as suction-feeders. Values for mechanical advantage ratios and suction indices in Antarctic fishes were within the range known for non-Antarctic fishes. The five Antarctic species do not possess dentition specialized for durophagous feeding; however, the high mechanical advantage ratio in the nototheniid and, to a lesser extent, in the zoarcids, suggests that durophagy may be possible.

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Brain and sensory organ morphology in Antarctic eelpouts (perciformes: Zoarcidae: Lycodinae)

Cited by 5 publications

References 46 publications

Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation

Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation

Brain and sense organ anatomy and histology of the Falkland Islands mullet, Eleginops maclovinus (Eleginopidae), the sister group of the Antarctic notothenioid fishes (Perciformes: Notothenioidei)

Feeding biomechanics of five demersal Antarctic fishes

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