Ecomorphology of retinal structures in zooplanktivorous haplochromine cichlids (Pisces) from Lake Victoria

Meer, H.J. van der; Anker, G. Ch.; Barel, C.D.N.

doi:10.1007/978-94-017-1356-6_8

Cited by 10 publications

(20 citation statements)

References 26 publications

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“…heusinkveldi Witte and Witte-Maas was restricted to the period with clear waters (Witte et al 2000). This concurs with the observation that, based on characteristics of their photoreceptor cells, Haplochromis pyrrhocephalus seemed better adapted to murky water than H. heusinkveldi (van der Meer et al 1995). The former appeared one of the most successfully recovering species and the latter seems to have disappeared (Witte et al 2000(Witte et al , 2007a.…”

Section: Discussionsupporting

confidence: 82%

“…Some species in these groups shifted from sand-bottom to mud-bottom habitats (Seehausen et al 1997b) and/or included more macro-invertebrates in their diet after recovery (Katunzi et al 2003;Kishe-Machumu et al 2008;E van Reenen, MJP van Oijen and F Witte, unpublished). Morphological changes, consistent with adaptations to changed environmental conditions, were also observed in several of the resurgent species (Kishe-Machumu et al 2008;Witte et al 2008;van der Meer et al 2012). These rapid morphological changes may reflect environmentally induced plasticity, heritable responses to recently changed natural selection, genetic introgression through hybridisation or, most likely, a combination of several of these factors.…”

Section: Discussionmentioning

confidence: 63%

“…In spite of this, the size, and thus photon catching ability, of double cones increased in relation to lens radius. At the same time, there was a reduction in single cone size, and thus short wave sensitivity (van der Meer et al 2012).…”

Section: Discussionmentioning

confidence: 95%

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Cichlid species diversity in naturally and anthropogenically turbid habitats of Lake Victoria, East Africa

et al. 2012

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During the past decades, major anthropogenic environmental changes occurred in Lake Victoria, including increased predation pressure due to Nile perch introduction, and decreases in water transparency and dissolved oxygen concentrations due to eutrophication. This resulted in a collapse of the haplochromine cichlids in the sub-littoral waters of the Mwanza Gulf in 1986-1990, followed by a recovery of some species in the 1990s and 2000s, when Nile perch densities declined. We studied two data sets: (1) haplochromines from sand and mud bottoms in the pre-collapse period; (2) haplochromines from sub-littoral areas during the precollapse, collapse and recovery periods. Water over mud is murkier and poorer in oxygen than water over sand, and differences in haplochromine communities in these natural habitats during the pre-collapse period may predict the effects of anthropogenic eutrophication during the collapse and recovery periods. In the pre-collapse period, haplochromine densities over sand and mud did not differ, but species richness over sand was 1.6 times higher than over mud bottoms. Orange-and white-blotched colour morphs were most common at the shallowest sand station. More specifically, insectivores and mollusc-shellers had higher numbers of species over sand than over mud, whereas for mollusc-crushers no difference was found. Laboratory experiments revealed that mollusc shelling was more affected by decreased light intensities than mollusc crushing. During the pre-collapse period, spawning occurred year-round in shallow areas with hard substrates and relatively clear water. In deeper areas with mud bottoms, spawning mainly occurred during months in which water clarity was high. No effects of hypoxia on spawning periods were found. It follows that clearer water seems to support differentiation in feeding techniques as well as year-round spawning, and both may facilitate species coexistence. Water clarity is also known to be important for mate choice. These observations may explain why, since the decline of Nile perch, haplochromine densities have recovered, the numbers of hybrids increased and species diversity in the current eutrophic sub-littoral waters has remained 70 % lower than before the environmental changes.

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Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 63%

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Cichlid species diversity in naturally and anthropogenically turbid habitats of Lake Victoria, East Africa

et al. 2012

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“…Absorbance spectra of the visual pigments of cones and rods can be measured directly by microspectrophotometry (Bowmaker, 1995) or inferred from electrophysiology (Parkyn and Hawryshyn, 2000;Whitmore and Bowmaker, 1989) and can give indications of spectral sensitivity and the potential for colour vision (Barry and Hawryshyn, 1999;Cameron, 2002). Histological studies can reveal the distribution of the various photoreceptor classes (Reckel et al, 2002;Van der Meer et al, 1995), complementing the physiological measurements of spectral sensitivity and providing estimations of visual acuity (Fritsches et al, 2003;Shand, 1997). However, none of these methods can define visual performance, which can only be determined by behavioural experiments (Douglas and Hawryshyn, 1990;White et al, 2004) involving either innate behaviours such as the optomotor response (Krauss and Neumeyer, 2003;Schaerer and Neumeyer, 1996) or behavioural activities such as feeding strategies (Job and Shand, 2001;Utne-Palm, 2002).…”

Section: Introductionmentioning

confidence: 99%

“…However, none of these methods can define visual performance, which can only be determined by behavioural experiments (Douglas and Hawryshyn, 1990;White et al, 2004) involving either innate behaviours such as the optomotor response (Krauss and Neumeyer, 2003;Schaerer and Neumeyer, 1996) or behavioural activities such as feeding strategies (Job and Shand, 2001;Utne-Palm, 2002). Correlations of these methods of investigation can give insights into the retinal mechanisms underlying visual performance, but can produce divergent results (Neave, 1984;Browman et al, 1990;Miller et al, 1993;Pankhurst et al, 1993;Van der Meer, 1994;Van der Meer, 1995). In the present study of the two-spotted goby, Gobiusculus flavescens (Fabricius), we have used microspectrophotometry (MSP) to determine the complement of its visual pigments.…”

Section: Introductionmentioning

confidence: 99%

Spectral sensitivity of the two-spotted gobyGobiusculus flavescens(Fabricius): a physiological and behavioural study

Utne‐Palm

Bowmaker

2006

Journal of Experimental Biology

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SUMMARY Microspectrophotometry of Gobiusculus flavescens photoreceptors revealed a single rod visual pigment (λmaxat 508 nm) and the three cone pigments (λmax 456, 531 and 553 nm). The cone population was dominated by identical double cones containing the middle-wave-sensitive (MWS)pigment, but with a small number of non-identical MWS/LWS(long-wave-sensitive) and identical LWS double cones. Small populations of large single cones also contained either the MWS or LWS pigment. The short-wave-sensitive (SWS) pigment was found in small single cones. Lens transmission was great reduced below 410 nm. The spectral sensitivity of the behaviourally determined reaction distance(RD) to prey at a high irradiance level 0.5 μmol m-2s-1) correlated with the maximum sensitivity of the MWS cones, both peaking around 530 nm. However, at a lower irradiance level (0.015 μmol m-2 s-1)such a correlation was not so apparent. The RD was greatly reduced, though still maintaining a peak around 530-550 nm, but with a relatively smaller reduction in RD at shorter wavelengths. Optomotor behaviour displayed a somewhat similar spectral sensitivity to the RD responses at the higher light intensity. However, the peak was at slightly longer wavelengths at 550 nm, suggesting a greater input from LWS cones to the optomotor response.

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Ecomorphological trends in the Artedidraconidae (Pisces: Perciformes: Notothenioidei) of the Weddell Sea

Lombarte¹,

Olaso

Bozzano³

2003

Antartic science

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An ecomorphological study was performed on ten species of the family Artedidraconidae, the most benthic of the suborder Notothenioidei. These species are sympatric on the shelf of the Weddell Sea. The results show that the four genera comprising the family (Artedidraco, Dolloidraco, Histiodraco and Pogonophryne) can be differentiated by just a few morphometric features of their sensory organs and mouth. The genera were also clearly defined by the composition of their diet (benthic and epibenthic), the size of their prey, and their bathymetric distribution. Comparison of the morphological and ecological data shows a very close connection between sensory organs development, the mouth and bathymetric distribution. The morphological and ecological divergence observed can be explained as the result of the rapid adaptive radiation of the artedidraconids. The results confirm that characteristics of the sensory organs and alimentary structures are very suitable for the ecomorphological study of fishes.

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Ecomorphology of retinal structures in zooplanktivorous haplochromine cichlids (Pisces) from Lake Victoria

Cited by 10 publications

References 26 publications

Cichlid species diversity in naturally and anthropogenically turbid habitats of Lake Victoria, East Africa

Cichlid species diversity in naturally and anthropogenically turbid habitats of Lake Victoria, East Africa

Spectral sensitivity of the two-spotted gobyGobiusculus flavescens(Fabricius): a physiological and behavioural study

Ecomorphological trends in the Artedidraconidae (Pisces: Perciformes: Notothenioidei) of the Weddell Sea

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