scholarly journals Oceanic adults, coastal juveniles: tracking the habitat use of whale sharks off the Pacific coast of Mexico

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3271 ◽  
Author(s):  
Dení Ramírez-Macías ◽  
Nuno Queiroz ◽  
Simon J. Pierce ◽  
Nicolas E. Humphries ◽  
David W. Sims ◽  
...  

Eight whale sharks tagged with pop-up satellite archival tags off the Gulf of California, Mexico, were tracked for periods of 14–134 days. Five of these sharks were adults, with four females visually assessed to be pregnant. At least for the periods they were tracked, juveniles remained in the Gulf of California while adults moved offshore into the eastern Pacific Ocean. We propose that parturition occurs in these offshore waters. Excluding two juveniles that remained in the shallow tagging area for the duration of tracking, all sharks spent 65 ± 20.7% (SD) of their time near the surface, even over deep water, often in association with frontal zones characterized by cool-water upwelling. While these six sharks all made dives into the meso- or bathypelagic zones, with two sharks reaching the maximum depth recordable by the tags (1285.8 m), time spent at these depths represented a small proportion of the overall tracks. Most deep dives (72.7%) took place during the day, particularly during the early morning and late afternoon. Pronounced habitat differences by ontogenetic stage suggest that adult whale sharks are less likely to frequent coastal waters after the onset of maturity.

Paleobiology ◽  
1991 ◽  
Vol 17 (4) ◽  
pp. 325-339 ◽  
Author(s):  
Steven C. Beadle

Under favorable circumstances, biogeographic and biostratigraphic data can be combined to identify accurately the time and place of origin of a given taxon, and to reconstruct the pattern of its subsequent radiation. This study considers the dendrasterid sand dollars, which are abundant today along the Pacific Coast of North America. The Neogene sand dollar record in this region is particularly good; in fact, sand dollars have traditionally been used as provincial index fossils.The dendrasterids originated in central California at the end of the Miocene; the oldest forms are dated at about 6.0–6.5 Ma. They spread south to Baja California during the Pliocene, and then north to Alaska during the Quaternary. This historical pattern is not an artifact of the record; it is consistent with independent paleogeographic evidence. The dendrasterids supplanted an older Mio-Pliocene sand dollar fauna; they are now completely dominant in the temperate coastal waters of the northeastern Pacific. They have reached this position in less than 7 m.y. since their first local appearance. The rapid rise of dendrasterids could be related to their aberrant morphology and behavior; these adaptations allow dendrasterids to suspension-feed, in a manner unique among living echinoids.Dendrasterids are characterized by “eccentric” test morphologies. Even the oldest species are highly eccentric; transitional forms are unknown. The first dendrasterids appear suddenly in the provincial “Jacalitos Stage,” above an unconformity which represents no more than about 1 m.y. They do not occur in the underlying units, although other fossil sand dollars are abundant. The dendrasterids may have arisen rapidly, through a heterochronic change in the development of older, noneccentric forms. Recent ontogenetic studies have documented the feasibility of this process.


Zootaxa ◽  
2008 ◽  
Vol 1908 (1) ◽  
pp. 51-56 ◽  
Author(s):  
NIEL L. BRUCE ◽  
REGINA WETZER

Collections made along the coast of California have revealed the presence of a species of Pseudosphaeroma Chilton, 1909, a genus common in New Zealand coastal waters. The genus is entirely Southern Hemisphere in distribution, and this record reports the introduction of a species of Pseudosphaeroma into the San Francisco and Central Coast region of California, the first reported occurrence of the genus as an invasive taxon, and the first record of the genus from the Northern Hemisphere. The genus is also recorded for the first time from the Galapagos and Argentina.


Author(s):  
Rafael Lemaitre ◽  
Ricardo Alvarez León

The Pacific coast of Colombia has been poorly explored, and its fauna is one of the least known in the tropical eastern Pacific. Although knowledge of the decapod fauna from this coast has recently increased, the information is scattered in numerous sources. A review of the literature showed that 378 decapods have been reported from this coast, including the islands of Gorgona and Malpelo. The numbers of species are distributed as follows; Dendrobranchiata, 18; Caridea,79; Thalassinidea, 13; Palinura, 6; Anomura, 61; and Brachyura, 201 .Twenty-seven species are known exclusively from the Colombian coast, three of which are endemic to the islands of Malpelo or Gorgona. A list of nominal species is presented, including information on distribution, important references, and synonyms under which the taxa have been reported for this coast. A summary of the history of explorations of the Pacific coast of Colombia as it relates to decapods, is presented. Zoogeographic affinities are briefly discussed for the marine species based on published distributions. Affinities are greatest with the Gulf of California (51.8%), followed by the Galápagos (28.6%), the Indo-Pacific (8.8%), and the Caribbean- Atlantic (7.7%).


Zootaxa ◽  
2021 ◽  
Vol 4974 (1) ◽  
pp. 197-200
Author(s):  
ALEXEI V. CHERNYSHEV

Marine heterobranch slugs of the order Runcinida comprise 61 species, most of which inhabit the Atlantic Ocean and are referred to the genus Runcina. The Runcinida of the Pacific Ocean have been much less studied to date: only 12 species, from the genera Metaruncina Baba, 1967, Rfemsia Chernyshev, 1999, Runcinida Burn, 1963, Runcinella Odhner, 1924, Pseudoilbia M. C. Miller & Rudman, 1968, and Runcina Forbes [in Forbes and Hanley], 1851, have been described from the region. Metaruncina, Rfemsia, and Runcinida are found in the Pacific Ocean only (Baba 1954, 1967; Burn 1963; Gosliner 1991; Chernyshev 1998, 1999, 2005, 2006). The genus Metaruncina, endemic from the Pacific coast of Asia, includes two species: M. setoensis (Baba, 1954) and M. nhatrangensis Chernyshev, 2005. The latter is the only runcinid described from the coastal waters of the South China Sea, where it was found in the bays of Nha Trang and Van Phong (Chernyshev 2005). During subsequent expeditions to the coastal waters of Vietnam, this species was also recorded from off Tho Chu Island (09°19’N, 103°30’E) and off Nam Du Island (09°43′ N, 104°23′ E). However, in addition to this common species, an undescribed species of Metaruncina was collected. A description of this new species is provided in the present paper. Type material was deposited at the Museum of the A.V. Zhirmunsky National Scientific Center of Marine Biology FEB RAS, Vladivostok, Russia (MIMB). 


2021 ◽  
Vol 58 (4) ◽  
pp. 403-407
Author(s):  
N. Y. Bárcenas de los Santos ◽  
F. N. Morales-Serna ◽  
R. M. Medina-Guerrero ◽  
V. Hernández-Covarrubias ◽  
A. Oceguera-Figueroa ◽  
...  

Summary From January to May 2015, a sample of 50 individuals of the Pacific sierra Scomberomorus sierra Jordan and Starks, 1895 captured off Mazatlán (southeastern Gulf of California, Mexico) were reviewed for helminths. A total of 6, 255 parasitic worms belonging to 11 species (9 in adult stage and 2 larvae) were obtained. Trematoda was the best represented group with 6 species of Didymozoidae Monticelli, 1888 and 1 of Bucephalidae Poche, 1907. In addition, 2 monogenean species and 2 of Nematoda were collected. In this study, the first molecular sequences for didymozoid species in Mexico were generated, and for Glomeritrema sp. at worldwide level. The most prevalent species were Didymocylindrus sp. (92 %) and Didymocystis scomberomori (MacCallum & MacCallum, 1916) (88 %), whereas the monogenean Thoracocotyle crocea MacCallum, 1913 reached the highest value of mean intensity (75.2). The coincidence between the helminthological composition established in our study and that reported for the same scombrid in 4 localities from the Mexican South Pacific (sharing 10 species) suggests that this group of species persistently parasitize S. sierra throughout its distribution along the Mexican Pacific coast; furthermore, due to the richness of didymozoids and the affinity of Thoracocotylidae species for S. sierra, both groups can be considered typical parasites of this fi sh.


2013 ◽  
Vol 04 (12) ◽  
pp. 1-13 ◽  
Author(s):  
Luz Elena Mateo-Cid ◽  
A. Catalina Mendoza-González ◽  
Luis E. Aguilar-Rosas ◽  
Raúl Aguilar-Rosas

2012 ◽  
Vol 92-93 ◽  
pp. 130-137 ◽  
Author(s):  
Ivan Valiela ◽  
Luis Camilli ◽  
Thomas Stone ◽  
Anne Giblin ◽  
John Crusius ◽  
...  

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