View allAll Photos Tagged benthic
Common Scoter
Irish Name:
Scótar
Scientific name:
Melanitta nigra
Bird Family:
Ducks
red
Conservation status
Status
Resident and winter visitor from the Continent to all Irish coasts between October and April.
Identification
Medium-sized, plump duck usually seen in large flocks offshore. At closer range, males with yellow knob at base of bill. All dark plumage, with no white on the wing. Males black, females sooty brown with paler cheeks.
Voice
Soft piping 'pju'.
Diet
During the summer the diet is varied and includes water plants, insect larvae and freshwater crustaceans. During the winter, they forage mostly in waters less than 20 m deep and with coarse sandy substrates. They feed predominantly on benthic bivalve molluscs.
Breeding
First recorded breeding in Ireland in the beginning of the 20th century at Lower Lough Erne. Numbers increased steadily - up to 150 pairs were estimated during the late 1960s. They nest on islands with dense covering of scrub and tree cover. The breeding population has declined since due to the increase in Mink, which predate the nests and young.
Wintering
Common Scoter are almost entirely marine during the winter, and tend to congregate in large flocks on shallow seas with sandy bottoms supporting their preferred prey.
This year when I visited San Ignacio lagoon on Mexico's Baja peninsula there did not seem to be as many whales around, especially mothers with calves. This was surprising because the entire North Pacific population migrates to a handful of lagoons in Baja to breed and give birth. But I read in the news that the population is the lowest since monitoring began, and that only five calves had been seen this year in San Ignacio lagoon. Even more worrying is that 70 Grey Whales have been found dead in Baja, looking thin and emaciated. The population decline was first noticed in 2019 and it is believed to be because of problems on the summer feeding grounds in the Bering Sea. They feed during the summer, then migrate to warmer waters to breed and give birth, but live off their fat reserves in winter, doing little feeding. But malnutritioned animals will not be in good enough condition to produce a healthy calf. Scientists are unsure why there is so little food in the Arctic seas but think it may be related to the lack of sea ice. Algae grows underneath sea ice, and this dies and falls to the sea bed, providing food for the benthic (bottom-living) invertebrates on which the Grey Whales feed.
Here is a Grey Whale tail fluke with water pouring off it as it dives. I took this in San Ignacio lagoon in late February this year. Here's hoping the population of these magnificent creatures can recover.
Sturgeon (from Old English styrġa ultimately from Proto-Indo-European *str̥(Hx)yón-) is the common name for the 28 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are descended from other, earlier acipenseriform fish, which date back to the Early Jurassic period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside paddlefish (Polyodontidae). The family is grouped into four genera: Acipenser (which is paraphyletic, containing many distantly related sturgeon species), Huso, Scaphirhynchus, and Pseudoscaphirhynchus. Two species (A. naccarii and A. dabryanus) may be extinct in the wild, and one (P. fedtschenkoi) may be entirely extinct. Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America. A Maastrichtian-age fossil found in Morocco shows that they also once lived in Africa.
Sturgeons are long-lived, late-maturing fishes with distinctive characteristics, such as a heterocercal caudal fin similar to those of sharks, and an elongated, spindle-like body that is smooth-skinned, scaleless, and armored with five lateral rows of bony plates called scutes. Several species can grow quite large, typically ranging 2–3.5 m (7–12 ft) in length. The largest sturgeon on record was a beluga female captured in the Volga Delta in 1827, measuring 7.2 m (23 ft 7 in) long and weighing 1,571 kg (3,463 lb). Most sturgeons are anadromous bottom-feeders, migrating upstream to spawn but spending most of their lives feeding in river deltas and estuaries. Some species inhabit freshwater environments exclusively, while others primarily inhabit marine environments near coastal areas, and are known to venture into open ocean.
Several species of sturgeon are harvested for their roe, which is processed into the luxury food caviar. This has led to serious overexploitation, which combined with other conservation threats, has brought most of the species to critically endangered status, at the edge of extinction.
Yanosteus longidorsalis, a member of the extinct acipenseriform family Peipiaosteidae from the Early Cretaceous (125–120 Mya) Yixian Formation in Liaoning, China
Acipenseriform fishes appeared in the fossil record some 174 to 201 million years ago, during the Early Jurassic, making them some of the earliest extant actinopterygian fishes.[5] True sturgeons appear in the fossil record during the Upper Cretaceous, with amongst the oldest known remains being a partial skull from the Cenomanian (100–94 million years ago) of Alberta, Canada. In that time, sturgeons have undergone remarkably little morphological change, indicating their evolution has been exceptionally slow and earning them informal status as living fossils. This is explained in part by the long generation interval, tolerance for wide ranges of temperature and salinity, lack of predators due to size and bony plated armor, or scutes, and the abundance of prey items in the benthic environment. They do, however, still share several primitive characteristics, such as heterocercal tail, reduced squamation, more fin rays than supporting bony elements, and unique jaw suspension.
Despite the existence of a fossil record, full classification and phylogeny of the sturgeon species has been difficult to determine, in part due to the high individual and ontogenic variation, including geographical clines in certain features, such as rostrum shape, number of scutes, and body length. A further confounding factor is the peculiar ability of sturgeons to produce reproductively viable hybrids, even between species assigned to different genera. While ray-finned fishes (Actinopterygii) have a long evolutionary history culminating in the most familiar fishes, past adaptive evolutionary radiations have left only a few survivors, such as sturgeons and gars.
The wide range of the acipenserids and their endangered status have made collection of systematic materials difficult. The factors have led researchers in the past to identify over 40 additional species that were rejected by later scientists. Whether the species in the Acipenser and Huso genera are monophyletic (descended from one ancestor) or paraphyletic (descended from many ancestors) is still unclear, though the morphologically motivated division between these two genera clearly is not supported by the genetic evidence. An effort is ongoing to resolve the taxonomic confusion using a continuing synthesis of systematic data and molecular techniques.
The phylogeny of Acipenseridae, as in the cladogram, shows that they evolved from the bony fishes. Approximate dates are from Near et al., 2012.
en.wikipedia.org/wiki/European_shag
The European shag or common shag (Phalacrocorax aristotelis) is a species of cormorant. It breeds around the rocky coasts of western and southern Europe, southwest Asia and north Africa, mainly wintering in its breeding range except for the northernmost birds. In Britain this seabird is usually referred to as simply the shag.[2] The scientific genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"). The species name aristotelis commemorates the Greek philosopher Aristotle.
Description
This is a medium-large black bird, 68 to 78 cm (27 to 31 in) long and with a 95-to-110-centimetre (37 to 43 in) wingspan. It has a longish tail and yellow throat-patch. Adults have a small crest in the breeding season. It is distinguished from the great cormorant by its smaller size, lighter build, thinner bill, and, in breeding adults, by the crest and metallic green-tinged sheen on the feathers. Among those differences are that a shag has a lighter, narrower beak; and the juvenile shag has darker underparts. The European shag's tail has 12 feathers, the great cormorant's 14 feathers. The green sheen on the feathers results in the alternative name green cormorant sometimes being given to the European shag.
Habitat
It feeds in the sea, and, unlike the great cormorant, is rare inland. It will winter along any coast that is well-supplied with fish.
The European shag is one of the deepest divers among the cormorant family. Using depth gauges, European shags have been shown to dive to at least 45 m (148 ft). European shags are preponderantly benthic feeders, i.e. they find their prey on the sea bottom. They will eat a wide range of fish but their commonest prey is the sand eel. Shags will travel many kilometres from their roosting sites in order to feed.
In UK coastal waters, dive times are typically around 20 to 45 seconds, with a recovery time of around 15 seconds between dives; this is consistent with aerobic diving, i.e. the bird depends on the oxygen in its lungs and dissolved in its bloodstream during the dive. When they dive, they jump out of the water first to give extra impetus to the dive.
It breeds on coasts, nesting on rocky ledges or in crevices or small caves. The nests are untidy heaps of rotting seaweed or twigs cemented together by the bird's own guano. The nesting season is long, beginning in late February but some nests not started until May or even later. Three eggs are laid. Their chicks hatch without down and so they rely totally on their parents for warmth, often for a period of two months before they can fly. Fledging may occur at any time from early June to late August, exceptionally to mid-October.
Subspecies
There are three subspecies:[4]
P. a. aristotelis – (Linnaeus, 1761): nominate, found in northwestern Europe (Atlantic Ocean coasts)
P. a. desmarestii – (Payraudeau, 1826): found in southern Europe, southwest Asia (Mediterranean and Black Sea coasts)
P. a. riggenbachi – Hartert, 1923: found in northwest African coast
The subspecies differ slightly in bill size and the breast and leg colour of young birds. Recent evidence suggests that birds on the Atlantic coast of southwest Europe are distinct from all three, and may be an as-yet undescribed subspecies.[5]
The name shag is also used in the Southern Hemisphere for several additional species of cormorants.
Example locations
The European shag can be readily be seen at the following breeding locations in the season (late April to mid July): Farne Islands, England; Deerness and Fowlsheugh, Scotland; Runde, Norway; Iceland, Faroe Islands and Galicia. In April 2017, eight new European shags were born in Monaco.[6]
The largest colony of European shags is in the Cíes Islands, with 2,500 pairs (25% of the world's population).
The bluecheek butterflyfish is one of the few fish species to have long-term mates. In the wild, the fish eats hard corals as well as benthic invertebrates. This is a common species which is found in areas with rich coral growth. They are frequently recorded in pairs or in small shoals. They have been known to occasionally hover in a stationary position for long periods beneath ledges of plate corals of the genus Acropora. It is oviparous species which forms pairs when spawning. This is normally during the day and the fishes emerge and are active at night. They are found at depths between 1 and 20 metres (3.3 and 65.6 ft).
The remarkable Hailey from Kona Diving Company found this tiny pom-pom crab (Lybia edmonsoni) for us.It carries a stinging anemone (Triactis producta) in each claw.
Flamingos
Pulicat Lagoon is the second largest brackish water lagoon in India, after Chilika Lake. Pulicat Lagoon is considered to be the second largest brackish water body in India measuring 759* km2. The Lagoon is one the three important wetlands to attract North-East Monsoon rain clouds during October to December season to Tamil Nadu. (AP) The lagoon was cut across in the middle the Sriharikota Link Road, which divided the water body into lake and marshy land. The lake encompasses the Pulicat Lake Bird Sanctuary.
Every year approximately 15,000 greater flamingos are reported to visit the lake along with pelicans, kingfishers, herons, painted storks, spoonbills and ducks. The highest concentrations of flamingo are found in the periphery of the lagoon where the water level is below40 centimetres (16 in). The concentrations of flamingos are also associated with high algal, fish and benthic diversity.
I haven't been able to dive for the last couple weekends d/t high surt, but this Saturday I went to Honaunau Bay to check on my frogfish friend. It has grown bulkier and darker and has added a couple more brown spots. Visibility was awful and this was the only decent shot I got. I hope to continue documenting this fish as it grows.
Typically restricted to rocky shores, black guillemots utilize the cliffs, crevices and boulders for their nests, hunting the inshore waters for benthic prey. Compared to other auks they forage fairly close to the colony, in the breeding season mostly in inshore waters more than 50m in depth, farther afield in the winter months.
They dive for food from the surface, swimming underwater. They mainly eat fish and crustaceans, also some mollusks, insects and plant material.