Geology topics

Alejandra G. Jaramillo

Publications and source records attributed to Alejandra G. Jaramillo.

4 recordsLinked to original sources

USGS2019

Parasitic copepods (Crustacea, Hexanauplia) on fishes from the lagoon flats of Palmyra Atoll, Central Pacific

We surveyed copepods parasitic on the fishes at Palmyra, a remote atoll in the Central Indo-Pacific faunal region. In total, we collected 849 individual fish, representing 44 species, from the intertidal lagoon flats at Palmyra and recovered 17 parasitic copepod species. The parasitic copepods were: Orbitacolax williamsi on Mulloidichthys flavolineatus ; Anuretes serratus on Acanthurus xanthopterus ; Caligus confusus on Carangoides ferdau , Carangoides orthogrammus , Caranx ignobilis , Caranx melampygus , and Caranx papuensis ; Caligus kapuhili on Chaetodon auriga and Chaetodon lunula ; Caligus laticaudus on Rhinecanthus aculeatus , Pseudobalistes flavimarginatus , M. flavolineatus , Upeneus taeniopterus , Chrysiptera glauca , and Epinephalus merra ; Caligus mutabilis on Lutjanus fulvus and Lutjanus monostigma ; Caligus randalli on C. ignobilis ; Caligus sp. on L. fulvus ; Caritus serratus on Chanos chanos ; Lepeophtheirus lewisi on A. xanthopterus ; Lepeophtheirus uluus on C. ignobilis ; Dissonus similis on Arothron hispidus ; Nemesis sp. on Carcharhinus melanopterus ; Hatschekia longiabdominalis on A. hispidus ; Hatschekia bicaudata on Chaetodon auriga and Chaetodon lunula ; Kroyeria longicauda on C. melanopterus and Lernanthropus sp. on Kyphosus cinerascens . All copepod species reported here have been previously reported from the Indo-Pacific but represent new geographical records for Palmyra, demonstrating large-scale parasite dispersion strategies.

ZooKeys↗

USGS2017

Monogenea of fishes from the lagoon flats of Palmyra Atoll in the Central Pacific

A survey of the monogeneans of fishes from the lagoon flats of Palmyra Atoll detected 16 species already reported from the Indo-West Pacific faunal region. A total of 653 individual fish from 44 species were collected from the sand flats bordering the lagoon of the atoll. Eighteen species of fish were infected with monogeneans. The monogenean species recovered were: Benedenia hawaiiensis on Acanthurus xanthopterus, Chaetodon auriga, Chaetodon lunula, Mulloidichthys flavolineatus, Pseudobalistes flavimarginatus and Rhinecanthus aculeatus; Ancyrocephalus ornatus on Arothron hispidus; Euryhaliotrema annulocirrus on Chaetodon auriga and Chaetodon lunula; Euryhaliotrema chrysotaeniae on Lutjanus fulvus; Euryhaliotrema grandis on Chaetodon auriga and Chaetodon lunula; Haliotrema acanthuri on Acanthurus triostegus; Haliotrema aurigae on Chaetodon auriga and Chaetodon lunula; Haliotrema dempsteri on Acanthurus xanthopterus; Haliotrema minutospirale on Mulloidichthys flavolineatus; Haliotrematoides patellacirrus on Lutjanus monostigma; Neohaliotrema bombini on Abudefduf septemfasciatus and Abudefduf sordidus; Acleotrema girellae and Acleotrema parastromatei on Kyphosus cinerascens; Cemocotylella elongata on Caranx ignobilis, Caranx melampygus and Caranx papuensis; Metamicrocotyla macracantha on Crenimugil crenilabris; and Pseudopterinotrema albulae on Albula glossodonta. All these monogenean–host combinations represent new geographical records. The monogenean species composition of the Palmyra Atoll is similar to that of the Hawaiian Islands. However, the number of species recovered was lower compared with other localities within the Indo-West Pacific, perhaps due to the geographical isolation of Palmyra Atoll.

Palmyra Atoll↗

USGS2016

The role of competition – colonization tradeoffs and spatial heterogeneity in promoting trematode coexistence

Competition – colonization tradeoffs occur in many systems, and theory predicts that they can strongly promote species coexistence. However, there is little empirical evidence that observed competition – colonization tradeoffs are strong enough to maintain diversity in natural systems. This is due in part to a mismatch between theoretical assumptions and biological reality in some systems. We tested whether a competition – colonization tradeoff explains how a diverse trematode guild coexists in California horn snail populations, a system that meets the requisite criteria for the tradeoff to promote coexistence. A field experiment showed that subordinate trematode species tended to have higher colonization rates than dominant species. This tradeoff promoted coexistence in parameterized models but did not fully explain trematode diversity and abundance, suggesting a role of additional diversity maintenance mechanisms. Spatial heterogeneity is an alternative way to promote coexistence if it isolates competing species. We used scale transition theory to expand the competition – colonization tradeoff model to include spatial variation. The parameterized model showed that spatial variation in trematode prevalence did not isolate most species sufficiently to explain the overall high diversity, but could benefit some rare species. Together, the results suggest that several mechanisms combine to maintain diversity, even when a competition – colonization tradeoff occurs.

Ecology↗

USGS2015

Two myxozoans from the urinary tract of topsmelt, Atherinops affinis

Two myxozoan species were observed in the kidney of topsmelt, Atherinops affinis , during a survey of parasites of estuarine fishes in the Carpinteria Salt Marsh Reserve, California. Fish collected on 3 dates in 2012 and 2013 were sectioned and examined histologically. Large extrasporogonic stages occurred in the renal interstitium of several fish from the first 2 collections (5/8, 11/20, respectively) and, in some fish, these replaced over 80% of the kidney. In addition, presporogonic and polysporogonic stages occurred in the lumen of the renal tubules, collecting ducts, and mesonephric ducts. The latter contained subspherical spores with up to 4 polar capsules, consistent with the genus Chloromyxum . For the third collection (15 May 2013, n = 30), we portioned kidneys for examination by histology, wet mount, and DNA extraction for small subunit ribosomal (SSU rDNA) gene sequencing. Histology showed the large extrasporogonic forms in the kidney interstitium of 3 fish and showed 2 other fish with subspherical myxospores in the lumen of the renal tubules with smooth valves and 2 spherical polar capsules consistent with the genus Sphaerospora. Chloromyxum -type myxospores were observed in the renal tubules of 1 fish by wet mount. Sequencing of the kidney tissue from this fish yielded a partial SSU rDNA sequence of 1,769 base pairs (bp). Phylogenetic reconstruction suggested this organism to be a novel species of Chloromyxum , most similar to Chloromyxum careni (84% similarity). In addition, subspherical myxospores with smooth valves and 2 spherical polar capsules consistent with the genus Sphaerospora were observed in wet mounts of 2 fish. Sequencing of the kidney tissue from 1 fish yielded a partial SSU rDNA sequence of 1,937 bp. Phylogenetic reconstruction suggests this organism to be a novel species of Sphaerospora most closely related to Sphaerospora epinepheli (93%). We conclude that these organisms represent novel species of the genera Chloromyxum and Sphaerospora based on host, location, and SSU rDNA sequence. We further conclude that the formation of large, histozoic extrasporogonic stages in the renal interstitium represents developmental stages of Chloromyxum species for the following reasons: (1) Large extrasporogonic stages were only observed in fish with Chloromyxum -type spores developing within the renal tubules, (2) a DNA sequence consistent with the Chloromyxum sp. was only detected in fish with the large extrasporogonic stages, and (3) several Sphaerospora species have extrasporogonic forms, but they are considerably smaller and are composed of far fewer cells.

California↗