Lecture 13: Teleostei 3: Lower Euteostei & Neoteleostei: Lepidogalaxiformes to Myctophiformes

How does the retractor dorsalis work in Neoteleostei

A muscle that originates on the vertebral column, extends anteriorly, and inserts on the upper pharyngeal jaws (UPJs); can move upper pharyngeal jaws to lower jaws a masticate prey at the back of the throat; e.g. bass, tuna, seahorses; grinding of prey & moving into esophagus

Order stomiiformes of Superorder Protocanthopterygii of subdivision Euteleostei

All marine "deep sea" fishes; highly predatory; eats whatever can fit into mouth ; most Bathypelagic zone

What define Neoteleostei as a monophyly

The retractor dorsalis: allows UPJ teeth to move backwards; processing/ milling of ingested items

What does the Salamander fish represent

The sister group to all remain Euteleosts

What makes the lanternfishes important in marine food webs(family Myctophidae of Order Myctophiformes of Neoteleostei)

Their daily migration from Bathypelagic (deep sea) to epipelagic; e.g. many birds feed on them in epipelagic zone

Epipelagic Zone in yellow

Top Ample light; 0-200 m Euphotic zone; a

Family Ipnopidae of Order Aulopiformes of Neoteleostei

Tripod fishes; some deepest dwelling vertebrates (live on sea floor) opportunistic predators with massive mouths and highly sensitive pectoral fins; Abyssopelagic zone; (elopomorph reminder)

Order Argentiniformes of Superorder Protocanthopterygii

Weird eye fishes (Family Opisthoproctidae) ; Herring smelts, Barreleyes, slickheads, etc;

Hadopelagic Zone in green

lowest zone; regions within deep oceanic trenches in the abyssal plain part of the aphotic zone; c Hadal

Subdivision Euteleostei

Debate about whether this group is monophyletic; We recognize it nonetheless!

Sexual dimorphism of family Salmoniae

Extreme, only develop during reproductive season (e.g. males have massive humps on posterior part of body) Kype: extension of the males jaws to form a hook-like structure

Order Salmoniformes of Superorder Protacanthopterygii

Family salmoniae important: "species flocks"; anadromous; commercial & recreational importance & evolutionary importance

Bathypelagic Zone in green

No sunlight reaches this zone (called midnight zone); 1000m-4000m part of the aphotic zone; c Bathyal

Do morphological characters define Subdivision Euteleostei

No, there are none. Furthermore, there is nor genetic data support. We recognize it nonetheless! [as do most text books -until a better solution is proposed]

Is family Umbridae monophyletic

No; (paraphyletic with respect to Esocidae)

What characterizes Order Myctophiformes of Neoteleostei

HIgh number of photophores on body; Organs that produce light! this is: mate recognition, sexually dimorphic-> males & females have different patterns) & important for taxonomy, species specific; blue light allows camouflage

Order Lepidogalaxiformes

Has the Salamander fish from family Lepidiogalaxidae; Previously considered a galaxiid, and placed in Order Osmeriformes (next slide). Now placed in its own order based on results of DNA-based phylogenetic studie

What allows Order stomiiformes of Superorder Protocanthopterygii of subdivision Euteleostei to digest large prey

Highly extendible stomach; not very big fishes

Order Aulopiformes of Neoteleostei

Lizardfishes, tripods, & allies; marine fishes

Family Synodontidae of Order Aulopiformes of Neoteleostei

Lizardfishes; Bombay duck; highly predatory; massive gape

What type of life cycle does family Salmonidae have

MOST Biphasic lifecycle (anadromous), in most cases they die when after spawning in marine environments; complicated with migration required atleast once

Mesopelagic Zone in green

Middle layer; faint filtered sunlight & twighlight zone; 1000m-4000m part of Disphotic zone; b Sublittoral

Neoteleostei

Massive, bass, seahorses, tuna, et.c

Family Salmoninae fishes

Salmons & trouts ; Prized sports fishes/commerically important, E.G.,

Body shape of family Umbridae

Stereotypical sagittiformes

What type of feeding mode are members of family umbridae of Order Escoiformes & location in environment

Ambush predators; live in swamps/ stagnant water

Abyssospelagic Zone in green

Called Abyss; 4000m & below to the Abyssal plain (typically 6000m) part of the aphotic zone; c Abyssal

Order Esociformes of Superorder Protocanthopterygii

Important family: umbridae (mudminnows) Not monophyletic (genetic studies); massive mouth; stocked in fisheries

Sample of non-anadromous member of family salmoniae

Kokanee; morph; tiny compare to sockeye; entire life cycle in freshwater

What happens to a male member of family Salmoninae during spawning season

Kype formation, an extension of the male's jaw to form a hook-like structure. The male loses his teeth, & develops spawning teeth

Family Alepicauridae of Order Aulopiformes of Neoteleostei

Lancetfishes; strange elopomorphs; Mesopelagic; skeletons like paper for low specific gravity to achieve neutral buoyancy; highly predatory

Order Myctophiformes of Neoteleostei

Lanternfishes, etc; bioluminescent photophores; entirely marine! Bathypelagic (deep sea) but migrate to epipelagic daily; incredibly small (30-40 mm)

Superorder Protacanthopterygii

Recent genetic studies have suggested that this group (and at least one of the included orders) is not monophyletic; may be paraphyletic; trouts, salmon, pikes, mudminnows, smelts; both fresh & marine fishes

Members of family Salmoninae of Order Salmniformes of Superorder Protacanthopterygii of Subdivision Euteleostei

Salmons, rainbow trouts; naturally in northern hemisphere but been introduced all over the world for aquaculture and recreational purposes

Important characteristic of family salmoninae

Sexual dimorphism during spawning period • Males develop spawning teeth, "kype" (extension of jaws)

Radical modification of Order stomiiformes of Superorder Protocanthopterygii of subdivision Euteleostei

Silvery body; this reflects any light making them invisible as silver covers the entire body

What is true about the males & females of Family Ipnopidae (tripod) & Alepisauridae (lancetfishes) of Aulopiformes of Neoteleostei

Simultaneous hermaphrodite - both males & females

Family Alepocephalidae of Order Argentiniformes of Superorder Protocanthopterygii fishes

Slickheads, some recent studies place within Ostarioclupeomorpha; A Problematic group; major current debate over placement of this group

Sample of anadromous member of family salmoniae

Sockeye salmon; anadromous morph; migrate for the purpose of reproduction

Anadromous

Spawn in freshwater, grow in sea, return to freshwater to spawn