Gilly William

• Stanford University

Synopsis Neural input is critical for establishing behavioral output, but understanding how neuromuscular signals give rise to behaviors remains a challenge. In squid, locomotion through jet propulsion underlies many key behaviors, and the jet is mediated by two parallel neural pathways, the giant and non-giant axon systems. Much work has been done...

Although the Gulf of California is widely recognized as a region of high productivity and biodiversity, recent oceanographic and ecological changes have had a significant impact on its overall health. We review the relevant history of the economically important fishery based on large Humboldt (jumbo flying) squid (Dosidicus gigas) (> 50 cm mantle-l...

Climatic variability exerts enormous pressures on the structure and function of open ocean ecosystems. Although the responses of primary producers and top predators to these pressures are being increasingly well-documented, little is known about how midtrophic communities respond to oceanographic and climatic variability. We address this knowledge...

Collective behaviors in biological systems such as coordinated movements have important ecological and evolutionary consequences. While many studies examine within‐species variation in collective behavior, explicit comparisons between functionally similar species from different taxonomic groups are rare. Therefore, a fundamental question remains: h...

Small-scale fisheries are critically important for livelihoods around the world, particularly in tropical regions. However, climate variability and anthropogenic climate change may seriously impact small-scale fisheries by altering the abundance and distribution of target species. Social relationships between fishery users, such as fish traders, ca...

Ionizing radiation is clinically used to treat neurological problems and reduce pathological levels of neural activity in the brain, but its cellular-level mechanisms are not well understood. Although spontaneous and stimulated synaptic activity has been produced in rodents by clinically and environmentally relevant doses of radiation, the effects...

An important aspect of the performance of many fast muscle fiber types is rapid excitation. Previous research on the cross-striated muscle fibers responsible for the rapid tentacle strike in squid has revealed the specializations responsible for high shortening velocity, but little is known about excitation of these fibers. Conventional whole-cell...

Over the past two decades, the Gulf of California (GOC) has experienced three strong El Niño events (1997–1998, 2009–2010, and 2015–2016), each of which was followed by a drastic reduction in mantle length of mature Humboldt squid, Dosidicus gigas (from >60 cm to <20 cm). However, it is unclear how the oceanographic changes associated with strong E...

Interannual oceanic oscillations, climate change, and extreme events present a significant and complex challenge to management of pelagic fisheries. In recent years, anomalous oceanographic and atmospheric conditions have been reported across the northeast Pacific, yet research results concerning the biophysical mechanisms impacting specific organisms,...

Squids display a wide range of swimming behaviors, including powerful escape jets mediated by the giant axon system. For California market squid (Doryteuthis opalescens), maintaining essential behaviors like the escape response during environmental variations poses a major challenge as this species often encounters intrusions of cold, hypoxic offsh...

Many squids are social cephalopods and demonstrate exceptionally high metabolic rates. However, all prior investigations of metabolism in social cephalopods have utilized individual animals. We measured oxygen consumption of the social squid Doryteuthis opalescens both in groups and with solitary individuals to examine the influence of grouping on...

Dosidicus gigas (the Humboldt squid) is a widely distributed and ecologically important predator in the eastern Pacific Ocean, but its mating behaviour is poorly understood. Individuals of this species have undergone a drastic change in size at maturity in the last years. We investigated mating activity of Humboldt squid in the Gulf of California i...

Muscles of the mesopelagic copepod Gaussia princeps (Arthropoda, Crustacea, Calanoida) are responsible for repetitive movements of feeding and swimming appendages that are too fast to be followed by eye. This paper provides a comparative functional and ultrastructural description of five muscles that have different contraction speeds and are locate...

Sperm storage is common in internally fertilizing animals, but is also present in several external fertilizers, such as many cephalopods. Cephalopod males attach sperm packets (spermatangia) to female conspecifics during mating. Females of eight externally fertilizing families comprising 25% of cephalopod biodiversity have sperm-storage organs (sem...

Seemingly chaotic waves of spontaneous chromatophore activity occur in the ommastrephid squid, Dosidicus gigas, in the living state and immediately after surgical disruption of all known inputs from the central nervous system. Similar activity is apparent in the loliginid, Doryteuthis opalescens, but only after chronic denervation of chromatophores...

This paper presents the design, development, and field results of an autonomous, deep-submergence, depth-controlled Lagrangian camera platform. Called the “Driftcam,” this relatively small system has been developed to freely probe midwater acoustic-scattering layers while being used in combination with active acoustics on a nearby research vessel....

We describe the morphology of egg masses and hatchlings of the squid, Lolliguncula diomedeae (Hoyle, 1904) based on individuals hatched in the laboratory from two egg masses collected in the Gulf of California near Santa Rosalía, Baja California Sur, Mexico, and identified with molecular techniques. The characteristics of the egg mass are described...

Dosidicus gigas (jumbo or Humboldt squid) is an ecologically relevant predator in the Gulf of California, Mexico, where it supports an economically valuable fishery. The commercial jumbo squid fishery in the Gulf declined steeply after an El Niño event in 2009-2010, and subsequent landings have remained at historically low levels in the relevant sq...

The backscatter properties of jumbo or Humboldt squid (Dosidicus gigas) were examined in-situ by projecting simulated sperm whale (Physter macrocephalus) clicks to tethered squids. The incident signal was a broadband click with a peaked frequency of approximately 17 kHz. Echoes were collect for three different aspect angles; (broadside, anterior,...

Dosidicus gigas (Humboldt or jumbo flying squid) is an economically and ecologically influential species, yet little is known about its natural behaviors because of difficulties in studying this active predator in its oceanic environment. By using an animal-borne video package, National Geographic's Crittercam, we were able to observe natural behav...

Understanding the processes that generate novel adaptive phenotypes is central to evolutionary biology. We used comparative analyses to reveal the history of tetrodotoxin (TTX) resistance in TTX-bearing salamanders. Resistance to TTX is a critical component of the ability to use TTX defensively but the origin of the TTX-bearing phenotype is unclear...

Miller et al. (2013; Mar Ecol Prog Ser 477:123−134) used bulk stable isotope analysis (SIA) and a Bayesian isotope-mixing model (SIAR) to assess the diet of the Humboldt squid Dosidicus gigas in the Northern California Current. Their conclusions starkly contrast decades of food habits and other research on this organism. The methods they employed a...

Squid are the largest jet propellers in nature as adults, but as paralarvae they are some of the smallest, faced with the inherent inefficiency of jet propulsion at low Reynolds number. In this study we describe the behavior and kinematics of locomotion in 1 mm paralarvae of Dosidicus gigas, the smallest squid yet studied. They swim with hop-and-si...

Climate-driven range shifts are ongoing in pelagic marine environments, and ecosystems must respond to combined effects of altered species distributions and environmental drivers. Hypoxic oxygen minimum zones (OMZs) in midwater environments are shoaling globally; this can affect distributions of species both geographically and vertically along with...

Jumbo squid (Dosidicus gigas) and purpleback squid (Sthenoteuthis oualaniensis) (Teuthida: Ommastrephidae) are thought to spawn in the eastern tropical Pacific. We used 10 years of plankton tow and oceanographic data collected in this region to examine the reproductive habits of these 2 ecologically important squid. Paralarvae of jumbo squid and pu...

Squid not only swim, they can also fly like rockets, accelerating through the air by forcefully expelling water out of their mantles. Using available lab and field data from four squid species, Sthenoteuthis pteropus, Dosidicus gigas, Illex illecebrosus and Loligo opalescens, including sixteen remarkable photographs of flying S. pteropus off the co...

Background/Question/Methods Selective pressures on animals will determine some of their anatomical features, and understanding how selective pressures act on specific structural features requires an understanding of local enviromental and biological stimuli. The chromatophore system in squids provides a novel example. In general, the density and s...

Dosidicus gigas (Humboldt or jumbo squid) (Orbigny, 1835) is the largest ommastrephid squid, reaching up to 1.2m mantle length and 65kg in weight. This pelagic squid is endemic to the eastern Pacific Ocean and is particularly abundant in the highly productive waters of the California and Humboldt Current systems, and the Costa Rica Dome upwelling r...

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño...

Long-term declines in oxygen concentrations are evident throughout much of the ocean interior and are particularly acute in midwater oxygen minimum zones (OMZs). These regions are defined by extremely low oxygen concentrations (<20-45 µmol kg(-1)), cover wide expanses of the ocean, and are associated with productive oceanic and coastal regions. OMZ...

Humboldt squid Dosidicus gigas have undergone a major range expansion in the northern California Current System (CCS) during the last decade. These squid are thought to migrate annually from Mexican waters into the CCS where they prey on many species, including several that support lucrative fisheries; however, swimming capabilities and features of...

We studied the locomotion and behavior of Dosidicus gigas using pop-up archival transmitting (PAT) tags to record environmental parameters (depth, temperature and light) and an animal-borne video package (AVP) to log these parameters plus acceleration along three axes and record forward-directed video under natural lighting. A basic cycle of locomo...

We used split-beam acoustic techniques to observe free-swimming of jumbo squid Dosidicus gigas during 4 cruises in the Gulf of California. Four-dimensional spatio-temporal data revealed that at night in shallow water, jumbo squid were using ascending, spiral-like swimming paths to emerge from extremely dense aggregations, and were likely foraging o...

Little is known about embryonic development of oceanic squids, yet such information is critical to a meaningful understanding of these ecologically and economically important species. Eggs of the Humboldt squid Dosidicus gigas were artificially fertilized and incubated at temperatures found throughout this species’ range (5 to 30°C). Successful dev...

Egg capsules of the squid Doryteuthis (= Loligo) opalescens were reared in the laboratory to assess the dependence of time-to-hatching (incubation time) and hatching success rate on temperature and light regime. Both incubation time and hatch duration were found to be inversely related to temperature. More than 96% of paralarvae hatch from eggs rea...

Most species within the genus Conus are considered to be specialists in their consumption of prey, typically feeding on molluscs, vermiform invertebrates or fish, and employ peptide toxins to immobilize prey. Conus californicus Hinds 1844 atypically utilizes a wide range of food sources from all three groups. Using DNA- and protein-based methods, w...

Diversity among Conus toxins mirrors the high species diversity in the Indo-Pacific region, and evolution of both is thought to stem from feeding-niche specialization derived from intra-generic competition. This study focuses on Conus californicus, a phylogenetic outlier endemic to the temperate northeast Pacific. Essentially free of congeneric com...

Dosidicus gigas and Sthenoteuthis oualaniensis (Teuthoidea: Ommastrephidae: Ommastrephinae) are abundant, ecologically important squid that co-occur in the eastern tropical Pacific. Little is known about the genetic basis of population structure in either species, although the presence of 2 species within S. oualaniensis has been suggested. We repo...

We deployed four pop-up archival-transmitting (PAT) tags on jumbo squid (Dosidicus gigas) collected in the Pacific Ocean off the main entrance to Magdalena Bay on the Baja California peninsula in June 2005. This is the first successful deployment of PAT tags on jumbo squid in an area outside the Gulf of Califor-nia. Summary data were obtained throu...

The Humboldt squid, Dosidicus gigas, is a voracious migratory predator, important prey for many species, and the target of an economically important fishery. However, information on the behavior, life history, and biomass of this species is limited. Current knowledge is based almost exclusively on fisheries records, which only contain nighttime obs...

Stomach contents were analyzed for 249 jumbo squid (Dosidicus gigas) of 35–80 cm mantle length. All squid were sampled in the central Gulf of California in 2005–07, primarily on the commercial fishing grounds of Santa Rosalia during different times of the year. Diet off Santa Rosalia was mainly composed of mesopelagic micronektonic organisms, mostl...

One of the most storied biological expeditions is the 1940 trip to the Sea of Cortez (Gulf of California) by author John Steinbeck and his close friend Edward F Ricketts, a professional biologist. Steinbeck and Ricketts visited intertidal sites around the Gulf and made extensive collections, taking notes on fauna and natural history. In 2004, we re...

The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology....

This study presents the first target strength measurements of Dosidicus gigas, a large squid that is a key predator, a significant prey, and the target of an important fishery. Target strength of live, tethered squid was related to mantle length with values standardized to the length squared of -62.0, -67.4, -67.9, and -67.6 dB at 38, 70, 120, and...

We use hydrographic data from the California Cooperative Oceanic Fisheries Investigations program to explore the spatial and temporal variability of dissolved oxygen (DO) in the southern California Current System (CCS) over the period 1984-2006. Large declines in DO (up to 2.1 mumol/kg/y) have been observed throughout the domain, with the largest r...