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Full-Text Articles in Biology

Cannibalism Causes Size-Dependent Intraspecific Predation Pressure But Does Not Trigger Autotomy In The Intertidal Gastropod Agaronia Propatula, Ariel Z. Cyrus, Jennifer Swiggs, Pilar Santidrian Tomillo, Frank V. Paladino, Winfried S. Peters Aug 2015

Cannibalism Causes Size-Dependent Intraspecific Predation Pressure But Does Not Trigger Autotomy In The Intertidal Gastropod Agaronia Propatula, Ariel Z. Cyrus, Jennifer Swiggs, Pilar Santidrian Tomillo, Frank V. Paladino, Winfried S. Peters

Winfried S. Peters

Autotomy of the foot is readily inducible in the predatory marine gastropod Agaronia propatula (Conrad, 1849), but the natural trigger of the autotomy response is obscure. Since cannibalistic predation has been observed in the species while interspecific predation on A. propatula has not, it was hypothesized that autotomy in A. propatula helps to defend against cannibalism. This hypothesis was tested in the present study. In our Costa Rican study population, autotomy as well as cannibalism occurred at significant rates; morphological indicators of foot regeneration suggested that 9–23% of the animals had autotomized previously, while about 5% of all observed predation …


The Cannibalistic Snail Agaronia Propatula Is Reluctant To Feed On Autotomized ‘Tails’ Of Conspecifics, Ariel Z. Cyrus, Winfried S. Peters Jun 2014

The Cannibalistic Snail Agaronia Propatula Is Reluctant To Feed On Autotomized ‘Tails’ Of Conspecifics, Ariel Z. Cyrus, Winfried S. Peters

Winfried S. Peters

Autotomy and cannibalism increase the complexity of the life history, population structure, and population dynamics of a species. Species in which autotomy is triggered by cannibalism have rarely been studied. It has been hypothesized that in the intertidal gastropod Agaronia propatula, autotomized tissues are highly attractive to cannibals and so increase the victim’s chance to escape. We tested the hypothesis by presenting autotomized ‘tails’ to foraging animals. The attack rates on autotomized ‘tails’ were lower than those on artificial objects reported previously. Autonomously moving autotomized ‘tails’ were more frequently ignored than non-moving and artificially moved ‘tail’ pieces. Thus, autotomized …


The Evolution Of Billfish, Andrew Blitman Dec 2013

The Evolution Of Billfish, Andrew Blitman

Andrew Blitman

No abstract provided.


Comparing Volunteer And Professionally Collected Monitoring Data From The Rocky Subtidal Reefs Of Southern California, Usa, David Gillett, Daniel Pondella, Jan Freiwald, Kenneth Schiff, Jennifer Caselle, Craig Shuman, Stephen Weisberg Apr 2012

Comparing Volunteer And Professionally Collected Monitoring Data From The Rocky Subtidal Reefs Of Southern California, Usa, David Gillett, Daniel Pondella, Jan Freiwald, Kenneth Schiff, Jennifer Caselle, Craig Shuman, Stephen Weisberg

Daniel Pondella

Volunteer-based citizen monitoring has increasingly become part of the natural resources monitoring framework, but it is often unclear whether the data quality from these programs is sufficient for integration with traditional efforts conducted by professional scientists. At present, the biological and physical characteristics of California’s rocky reef kelp forests are concurrently monitored by two such groups, using similar methodologies—underwater visual census (UVC) of fish, benthic invertebrates, and reef habitat, though the volunteer group limits their sampling to transects close to the reef surface and they use a more constrained list of species for enumeration and measurement. Here, we compared the …


Sharks Of The Devonian, Andrew Blitman Dec 2011

Sharks Of The Devonian, Andrew Blitman

Andrew Blitman

No abstract provided.


Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters Sep 2009

Life History, Sexual Dimorphism And 'Ornamental' Feathers In The Mesozoic Bird Confuciusornis Sanctus., Winfried S. Peters, Dieter Stefan Peters

Winfried S. Peters

The life history of Confuciusornis sanctus is controversial. Recently, the species’ body size spectrum was claimed to contradict osteohistological evidence for a rapid, bird-like development. Moreover, sexual size dimorphism was rejected as an explanation for the observed bimodal size distribution since the presence of elongated rectrices, an assumed ‘male’ trait, was uncorrelated with size. However, this interpretation (i) fails to explain the size spectrum of C. sanctus which is trimodal rather than bimodal, (ii) requires implausible neonate masses and (iii) is not supported by analogy with sexual dimorphisms in modern birds, in which elongated central rectrices are mostly sex-independent. Available …


The Value Of A Net‐Cage As A Fish Aggregating Device In Southern California, Daniel Pondella Jan 2009

The Value Of A Net‐Cage As A Fish Aggregating Device In Southern California, Daniel Pondella

Daniel Pondella

There is an urgent need for primary data that can be used to quantify the value of marine aquaculture facilities that also describe influences on the surrounding natural ecosystem and its wild fish communities. Divers completed 360 transect replicates below a net-cage and at nearby and distant rocky reefs off Catalina Island, California, estimating the species abundance and size class of all conspicuous fishes in the water column. We observed 10,234 fishes aggregating below the net-cage with a mean annual density of 142 (SE ± 30) per 100 m2 and diversity H′ 2.29. At the adjacent reference reef, we counted …


Demographic Parameters Of Yellowfin Croaker, Umbrina Roncador (Perciformes: Sciaenidae), From The Southern California Bight, Daniel Pondella, John Froeschke, Lynne Wetmore, Eric Miller, Charles Valle, Lea Medeiros Sep 2008

Demographic Parameters Of Yellowfin Croaker, Umbrina Roncador (Perciformes: Sciaenidae), From The Southern California Bight, Daniel Pondella, John Froeschke, Lynne Wetmore, Eric Miller, Charles Valle, Lea Medeiros

Daniel Pondella

The yellowfin croaker, Umbrina roncador Jordan & Gilbert, 1882, is a common nearshore and surf-zone species in the southern California bight. Age was determined for individuals (n = 1,209) using annual increments in otoliths, and size at age was modeled using the von Bertalanffy growth curve (L∞ = 307.754 mm, k = 0.278 yr−1, t0 = −0.995 yr; maximum age = 15 yr). Females (L∞= 313.173 mm, k = 0.307 yr−1, t0 = −0.771 yr) grew significantly faster and larger than males (L∞= 298.886, k = 0.269 yr−1, t0 = −1.072 yr). Age and growth modeling based upon otolith length …


Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella Sep 2007

Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella

Daniel Pondella

The black perch, Embiotoca jacksoni Agassiz, 1853, is a common reef fish associated with nearshore marine habitats of California, with the majority of the population occurring within the Southern California Bight. Black perch were collected throughout southern California from Santa Barbara to Carlsbad, including Santa Catalina Island, to determine their physical characteristics, growth, sex ratio, periodicity of reproduction, and length of gestation. Courtship observations were conducted using scuba along the King Harbor Breakwater in Redondo Beach, California, from January 2004 to December 2005 to verify periodicity of courting and associated reproductive behaviors. Specimens captured ranged from 75 to 220 mm …


Fisheries Independent Assessment Of A Returning Fishery: Abundance Of Juvenile White Seabass (Atractoscion Nobilis) In The Shallow Nearshore Waters Of The Southern California Bight, 1995–2005, Larry G. Allen, Daniel J. Pondella Ii, Michael A. Shane Dec 2006

Fisheries Independent Assessment Of A Returning Fishery: Abundance Of Juvenile White Seabass (Atractoscion Nobilis) In The Shallow Nearshore Waters Of The Southern California Bight, 1995–2005, Larry G. Allen, Daniel J. Pondella Ii, Michael A. Shane

Daniel Pondella

Nearshore, coastal and embayment areas off southern California were sampled to determine the spatial and temporal patterns abundance and size distributions of young white seabass in the shallow (5–14 m) waters from Santa Barbara south to Imperial Beach off San Diego. A total of 19 stations, 13 in nearshore coastal waters and 6 in embayments, dispersed along the Southern California Bight were surveyed in each sampling month using 45.7 m variable mesh, monofilament gill nets. In the 11-year period of sampling (April 1995–June 2005), a total of 8075 juvenile white seabass was captured in 42 sampling months. The mean catch-per-unit-effort …


Ecology Of Marine Fishes : California And Adjacent Waters, Larry Allen, Daniel Pondella, Michael Horn Dec 2005

Ecology Of Marine Fishes : California And Adjacent Waters, Larry Allen, Daniel Pondella, Michael Horn

Daniel Pondella

Fundamental ideas in marine ecology have emerged from the study of marine fishes. This unique, authoritative, and accessible reference, compiled by 35 luminary ecologists, evolutionary biologists, and ichthyologists, provides the first-ever synthesis and interpretation of the large, often daunting, body of information on the ecology of marine fishes. Comprehensive and generously illustrated, this volume focuses on the fauna of the eastern pacific, paying particular attention to the California coast, which is among the most diverse and best studied of all marine ecosystems.


The Reef Fish Assemblage Of The Outer Los Angeles Federal Breakwater, 2002–2003, John Froeschke, Larry Allen, Daniel Pondella Jul 2005

The Reef Fish Assemblage Of The Outer Los Angeles Federal Breakwater, 2002–2003, John Froeschke, Larry Allen, Daniel Pondella

Daniel Pondella

The conspicuous and cryptic fish assemblage of the Los Angeles Federal Breakwater was assessed from 2002 to 2003. Thirty-five species were observed or collected during the study period. The assemblage of cryptic fishes was composed primarily of a mix of Oregonian and San Diegan, species including snubnose sculpin (Orthonopias triacis), coralline sculpin (Artedius corallinus) and blackeye goby (Rhinogobiops nicholsii). The species composition of conspicuous fishes was approximately equal between taxa from these two provinces. Blacksmith (Chromis punctipinnis), black perch (Embiotoca jacksoni) and kelp bass (Paralabrax clathratus) dominated the assemblage of conspicuous fishes. Species composition reflects the localized cool temperature regime …


The Phylogeny Of Paralabrax (Perciformes: Serranidae) And Allied Taxa Inferred From Partial 16s And 12s Mitochondrial Ribosomal Dna Sequences, Daniel Pondella, Matthew Craig, Jens Frank Sep 2003

The Phylogeny Of Paralabrax (Perciformes: Serranidae) And Allied Taxa Inferred From Partial 16s And 12s Mitochondrial Ribosomal Dna Sequences, Daniel Pondella, Matthew Craig, Jens Frank

Daniel Pondella

Partial sequences of 16S and 12S mitochondrial ribosomal DNA were used to examine the phylogenetic relationships of the primarily eastern Pacific genus Paralabrax (Perciformes: Serranidae) and allied taxa. Paralabrax is considered a basal serranine, which is itself considered the basal subfamily in the Serranidae. Multiple serranines reported closely related to Paralabrax from the genera Serranus, Hypoplectrus, Cratinus, and Centropristis were used as outgroups. Species from the remaining two subfamilies, Epinephilinae and Anthiinae, of the Serranidae were also used in the analyses. The tree of the Serranidae was rooted with the families Polyprionidae and Priacanthidae. Paralabrax, the Serranidae, and the Serraninae …


Analysis Of Age And Growth In Two Eastern Pacific Groupers (Serranidae: Epinephelinae), Matthew Craig, Daniel Pondella, John Hafner Oct 1999

Analysis Of Age And Growth In Two Eastern Pacific Groupers (Serranidae: Epinephelinae), Matthew Craig, Daniel Pondella, John Hafner

Daniel Pondella

In an attempt to characterize species specific-growth rates of two Eastern Pacific groupers, individuals from two sympatric species, Epinephelus labriformis (n = 173), and Cephalopholis panamensis (n = 127), were collected at various localities in Mexico and the Galápagos archipelago in 1997 and 1998. Sagittal otoliths were removed, and age of each individual was determined by direct visual inspection of annuli present following sectioning. Length/weight relationships were determined, and growth curves were generated using the von Bertalanffy growth model. The two species demonstrated similar growth rates, yet, as determined by the von Bertalanffy parameters, E. labriformis tended towards a larger …


Pollination Of The Crown Imperial Fritillaria Imperialis By Great Tits Parus Major, Winfried S. Peters, Michael Pirl, Gerhard Gottsberger, Dieter Stefan Peters Feb 1995

Pollination Of The Crown Imperial Fritillaria Imperialis By Great Tits Parus Major, Winfried S. Peters, Michael Pirl, Gerhard Gottsberger, Dieter Stefan Peters

Winfried S. Peters

Visitations of flowers of the Crown Imperial by Great Tits at two different locations in Hessen, Germany, in 1990 and 1993 are described. The observations prove that flowers were visited because of the nectar; most likely pollination occurs during this visits. Similar reports from Europe are discussed. The significance of specific interactions including ecological generalists such as the Great Tit is considered in the context of the phylogenetic reconstruction of the development of co-adaptive syndroms.


Factors Affecting The Abundance Of Juvenile Fish Species On A Temperate Artificial Reef, Daniel Pondella, John Stephens Aug 1994

Factors Affecting The Abundance Of Juvenile Fish Species On A Temperate Artificial Reef, Daniel Pondella, John Stephens

Daniel Pondella

In contrast to most artificial reefs which are placed at relatively deep depths so as not to interfere with shipping, rocky breakwaters provide important habitat in the intertidal-shallow subtidal zone. This zone is especially preferred for recruitment by many rocky shore fishes. The breakwaters of King Harbor, Redondo Beach, California enhance this zone. Further, the lee of the outer breakwater provides a stable, quiet water area for numerous Young-of-Year (YOY) fishes. By means of SCUBA we monitored YOY abundance from 1986-1990. During these five years there were dramatic natural and anthropogenic disturbances of the habitat. With little inter-annual variation of …