|
|
.gif)
Welcome to NewEnglandSharks.com Links to other pages are at the bottom of each page. |
Lamnidae shark family We are going to take a look at the Lamnidae family, because 3 of its 5 members; the white shark, porbeagle and shortfin mako are in our New England waters. |
Biologists pronounce the "ae" on the end of Lamnidae as a ee . They also pronounce a "ch" combination in the Greek/Latin scientific names as a hard K. Dont confuse the shark order Lamniformes, with the shark family Lamnidae. There are 7 families in the order Lamniformes, the Lamnidae family is just one of those groupings. There are approx. 500 shark species placed into 8 Orders and broken down into 34 shark families. The Lamnidae family has five very interesting members. Two of them, the white and the shortfin mako are celebrity sharks. Both are well know all over the world. The white for its interaction with swimmers and surfers, and the shortfin mako for its interaction with anglers and boaters. ("Interaction" is a euphemism for: nasty and sometimes fatal encounters.") Unique biological characteristics are the deciding factors as to which family a shark will be assigned. Looking alike won't get you into the same shark family. The blueshark, lemon, bull and tiger sharks are all members of the much larger 53 member Carcharhinidae family. Those species don't look anything alike in color, fin structure or body shape. There is no way you could mistake one for the other. Some others in that Carcharhinidae family look very much alike i.e., the sandbar, dusky, and bignose sharks, and the blacktips and spinner sharks are difficult to tell apart. The Lamnidae family sharks have the same characteristics in body shape and fin structure, and do look alike; which results in the white, mako and porbeagle getting continuously mistaken for one another. |
Some info on the five Lamnidae family members. White: Carcharodon carcharias – New England is the normal range of the white shark. The white shark is the only member of this Lamnidae family with serrated teeth. Protected as of April 1997, white sharks should be released unharmed. Porbeagle: Lamna nasus - New England is the normal range of the porbeagle -they are here year round. They look somewhat like a small white, or a chubby mako. They have a white strip or white patch on the back bottom of the dorsal fin and a secondary keel on the tail. Only two shark species have a secondary keel on their tail; the other species is the salmon shark, which is also in this Lamnidae family. Porbeagle teeth have protrusions at the base and the teeth are smooth edged. Salmon shark: Lamna ditropis - Not in the Atlantic. It is on the West Coast and Alaska-referred to by some as the Pacific Porbeagle. Lacks a white patch on the dorsal, and has very noticeable dark spots on its white underside, and a shorter snout than our porbeagle, Lamna nasus. It has the same type of teeth, which have protrusions at the base, and the teeth are not serrated. Shortfin Mako: Isurus oxyrinchus - New England is the normal range of the shortfin mako. They are record size in New England waters. A great jumping game fish. The area under the lower jaw and snout will be white, where as the longfin mako will have a dark area in those areas. Very fast! Very dangerous to anglers! The mako has long dagger like teeth with no serrations or cusps at the bottom. Very large mako's teeth are shaped somewhat similar to those of a white shark-without the serrations. Longfin Mako: Isurus paucus - not in coastal New England. Found well offshore of our south eastern states, and in Cuban waters. When hooked, a jumper like the shortfin mako. It has long swept back pectorals, and the area under its lower jaw is dark. Its eyes are larger than those of the shortfin mako. The longfin mako does not have as good a system for bringing warm blood back to the muscles as the other members of this warm bodied family. The Longfin's flesh is considered to be of poor quality. |
The teeth on the sides of the jaw have gaps between them, not abutting like ours, or many other shark species. Sharks in this family have conical shaped snouts, and long gill slits. |
The Lamnidae sharks have very small 2nd dorsal fins. Much smaller than most other sharks. The relationship of these 2nd dorsal fins to the anl fin below, can help identify the species. For example; the porbeagles 2nd dorsal is directly over, or slightly toward the tail in relation to the anal fin. The mako's 2nd dorsal is slightly ahead of the anal fin. The white shark's 2nd dorsal is much father ahead. |
More Characteristics of the Lamnidae family They are warm- bodied, and able to consistently maintain a body temperature about 10-18 deg. F above the existing water temperature. This gives them energy to the muscles while swimming in cool water. Being warm bodied doesn't directly translate into being able to withstand cold water. For example; the two species of makos avoid cold water while the porbeagles and salmon sharks thrive in it. The white sharks can also withstand cool water. The whites have a wide range of temperature tolerance. This group of sharks, as do many other species, lacks a nictitating membrane to protect their eyes. (other shark species in our area that do not have a nictitating membrane are the thresher, sandtiger, dogfish and basking shark .) They can roll their eyes back if they need eye protection. A mako rarely does this. The third tooth left or right of the center of the upper jaw will be smaller than the other teeth in that area. Take a look when a white opens its mouth on TV or the movies. |
porbeagle |
mako |
Shark species have more than one type of eye; such as a contrasting Iris, with vertical slit pupils; horizontal slit pupils, and some species have more rounded pupils. All Lamnidae family sharks have black eyes-and no protective membrane for their eyes. |
porbeagle |
A noticeable characteristic of Lamnidae family sharks is the flared out body section just before the tail. (basking sharks which are not in the Lamnidae family also have this characteristic as do swordfish) A mako, Isurus oxyrinchus will have a flared out section; a blueshark, Prionace glauca will not. In the photo below a blue colored mako is easily distinguished from a blueshark by the flared out tail section. |
white |
porbeagle |
mako |
-------New England |
You can see from the body shapes below how easy it is to get a mako, white or porbeagle mistaken for another Lamnidae family species. |
porbeagle |
---New England |
porbeagle |
--------New England |
mako |
Don't let the blue color fool you-look at the flared out sectiion going into the tail |
Notice the mako's pointed snout. |
notice white patch |
This is a small white shark. Look closely at the dorsal fin, and the relationship of the anal to the second dorsal fin. Notic the second small dorsal fin is well ahead of the anal fin below it. |